Study of gas (CNG) SI engine with pre-chamber. Improvement of the indicated thermal efficiency on lean mixture with EGR and supercharging; Fukushitsushiki hibana tenka asshuku tennen gas (CNG) engine ni kansuru kenkyu. Kakyu to EGR ni yoru kihakuiki no netsukoritsu kaizen

Energy Technology Data Exchange (ETDEWEB)

Yonetani, H.; Fukutani, I. [Polytechnic University, Kanagawa (Japan)

1998-10-15

As lean burn of compressed natural gas (CNG) is applied to conventional gasoline engines, a combustion period largely increases, resulting in large combustion fluctuation and low thermal efficiency. Heterogeneous spacial air/fuel ratios also have an effect on combustion in lean burn area. By preparing a pre-chamber for a combustion chamber of high- compression ratio CNG pre-mixing SI engines to utilize premixture turbulence, rapid flame propagation is obtained in lean burn area, resulting high combustion performance. Furthermore, study was made on improvement of combustion performance in lean burn area under various compression ratios, intake pressures, pre-chamber shapes and EGR ratios. As a result, lean burn operation at high intake pressure by supercharging showed possible improvement of a thermal efficiency and expansion of inflammable limits. Higher thermal efficiency in lean burn area was also obtained by using higher compression ratios considering heat loss. Although EGR was effective in controlling NOx formed in lean burn area, strict control of both air excess rate and EGR rate was required to prevent lower thermal efficiency. 2 refs., 8 figs., 1 tab.

Lean-burn stratified combustion at gasoline engines; Magere Schichtverbrennung beim Ottomotor

Energy Technology Data Exchange (ETDEWEB)

Breitbach, Hermann [Daimler AG, Stuttgart (Germany). Entwicklung Einspritzung und Betriebsstoffe; Waltner, Anton [Daimler AG, Stuttgart (Germany). Verbrennungsentwicklung Pkw-Ottomotoren; Landenfeld, Tilo [Robert Bosch GmbH, Schwieberdingen (Germany). Hochdruckeinspritzung Piezo; Porten, Guido [Robert Bosch GmbH, Schwieberdingen (Germany). Systementwicklung Benzindirekteinspritzung

2013-05-01

Spray-guided lean-burn combustion is an integral part of the Mercedes-Benz technology strategy for highly efficient and clean gasoline engines. With regard to the excellent fuel efficiency combined with outstanding specific power, a good combustion system robustness and the low particulate emissions, the concept offers a very good cost/benefit ratio especially for the Euro 6 emission legislation. Thus, Mercedes-Benz believes, that the sprayguided lean-burn combustion offers the by far highest future viability of gasoline engine combustion systems.

Physicochemical effects of varying fuel composition on knock characteristics of natural gas mixtures

NARCIS (Netherlands)

Gersen, Sander; van Essen, Martijn; van Dijk, Gerco; Levinsky, Howard

2014-01-01

The physicochemical origins of how changes in fuel composition affect autoignition of the end gas, leading to engine knock, are analyzed for a natural gas engine. Experiments in a lean-burn, high-speed medium-BMEP gas engine are performed using a reference natural gas with systematically varied

NOx storage and reduction over a lean-burn automotive catalyst

NARCIS (Netherlands)

Scholz, C.M.L.

2007-01-01

Nowadays, there is an increased interest in lean-burn technologies, i.e. diesel and lean-burn gasoline engines, mainly due to their higher fuel efficiency compared to conventional gasoline engines. Lean-burn engines work under excess oxygen and consequently produce oxygen-rich exhaust. This

Model predictive control of a lean-burn gasoline engine coupled with a passive selective catalytic reduction system

Energy Technology Data Exchange (ETDEWEB)

Chen, Pingen [Tennessee Technological University (TTU); Lin, Qinghua [Tennessee Technological University (TTU); Prikhodko, Vitaly Y. [ORNL

2017-10-01

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuel penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.

An overview of exhaust emissions regulatory requirements and control technology for stationary natural gas engines

International Nuclear Information System (INIS)

Ballard, H.N.; Hay, S.C.; Shade, W.N. Jr.

1992-01-01

In this paper a practical overview of stationary natural gas engine exhaust emissions control technology and trends in emissions regulatory requirements is presented. Selective and non-selective catalytic reduction and lean burn technologies are compared. Particular emphasis is focussed on implications of the Clean Air Act of 1990. Recent emissions reduction conversion kit developments and a practical approach to continuous monitoring are discussed

Environmental optimisation of natural gas fired engines. Measurement on four different engines. Project report

Energy Technology Data Exchange (ETDEWEB)

Kvist, T.

2010-10-15

The emissions of NO{sub x}, CO and UHC as well as the composition of the hydrocarbon emissions were measured for four different stationary lean burn natural gas fired engines installed at different combined heat and power (CHP) units in Denmark. The units have been chosen to be representative for the natural gas engine based on power production in Denmark. The NO{sub x} emissions were varied from around 200 to 500 mg/m3(n) by varying the ignition timing and the excess of air. For each of the examined engines measurements were conducted at different combinations of ignition timing and excess of air. The measurements showed the NO{sub x} emissions were relatively more sensitive to engine setting than UHC, CO and formaldehyde emissions. By reducing the NO{sub x} emissions to 40 % of the initial value (from 500 to 200 mg/m3(n)) the UHC emission were increased by 10 % to 50 % of the initial value. The electrical efficiency was reduced by 0,5 to 1,0 % point. (Author)

An experimental investigation of a lean-burn natural-gas pre-chamber spark ignition engine for cogeneration; Swiss Motor. Modification d'un moteur diesel pour le fonctionnement au gaz naturel en cogeneration. Fonctionnement avec prechambre de combustion

Energy Technology Data Exchange (ETDEWEB)

Roethlisberger, R.; Favrat, D.

2001-07-01

This thesis presented at the Department of Mechanical Engineering of the Swiss Federal Institute of Technology in Lausanne describes the conversion and testing of a commercial diesel engine for use as a lean-burn, natural gas, pre-chamber, spark ignition engine with a rated power of 150 kW, in combined heat and power (CHP) plants. The objective of the investigations - to evaluate the potential of reducing exhaust gas emissions - is discussed in detail with respect to NO{sub x} and CO emissions. The approach adopted includes both experimental work and numerical simulation. The report describes the testing facilities used. The results obtained with experimental spark-plug configurations based on simulation results are presented and the influence of various pre-chamber configuration variants are discussed. The results of the tests are presented and the significant reduction of NO{sub x}, CO and unburned-hydrocarbon (THC) emissions are discussed. The authors state that the engine, which achieves a fuel efficiency of more than 36.5%, fulfils the Swiss requirements on exhaust gas emissions. Also, ways of compensating for the slight loss in fuel-conversion efficiency in the pre-chamber configuration are discussed.

Development of natural gas rotary engines

Science.gov (United States)

Mack, J. R.

1991-08-01

Development of natural gas-fueled rotary engines was pursued on the parallel paths of converted Mazda automotive engines and of establishing technology and demonstration of a test model of a larger John Deer Technologies Incorporated (JDTI) rotary engine with power capability of 250 HP per power section for future production of multi-rotor engines with power ratings 250, 500, and 1000 HP and upward. Mazda engines were converted to natural gas and were characterized by a laboratory which was followed by nearly 12,000 hours of testing in three different field installations. To develop technology for the larger JDTI engine, laboratory and engine materials testing was accomplished. Extensive combustion analysis computer codes were modified, verified, and utilized to predict engine performance, to guide parameters for actual engine design, and to identify further improvements. A single rotor test engine of 5.8 liter displacement was designed for natural gas operation based on the JDTI 580 engine series. This engine was built and tested. It ran well and essentially achieved predicted performance. Lean combustion and low NOW emission were demonstrated.

A study on the criterions of lean burn limit for an LPG EFI engine. Paper no. IGEC-1-140

International Nuclear Information System (INIS)

Li, L.; Wang, Z.; Xiao, Z.; Wang, H.; Deng, B.; Su, Y.

2005-01-01

Based on electronic low-pressure gaseous injection, the comparing analysis of several methods for the criterions of lean burn limit in an LPG engine is presented. Experiments are carried out in a single cylinder, four-stroke, water-cooled, 125cc engine with electronic LPG injection. According to the analysis of multi-parameters in and out cylinder, it shows that variation coefficient of indicated pressure which is the classical judgment of lean burn limit, the HC emission, HC emission rising gradient, the misfiring rate and the variation coefficient of the crank angle of the maximum combustion pressure can be as the criterions for lean burn limit. For the test engine, 15% as variation coefficient of indicative mean pressure, 500 x 10 -6 as HC emission, 2000 x 10 -6 as HC emission rising ratio, 1% as misfiring rate and 50% as variation coefficient of the crank angle of the maximum combustion pressure can be as the judgment criterions of LPG lean burn limits. (author)

Development of lean burn gas engines using pilot fuel for ignition source; Developpement d'un moteur a gaz avec pre-injection de carburant pour la source d'allumage

Energy Technology Data Exchange (ETDEWEB)

Sakonji, T.; Saito, H.; Sakurai, T. [Tokyo Gas Co., Ltd. (Japan); Hirashima, T.; Kanno, K. [Nissan Diesel Motor Co., Ltd. (Japan)

2000-07-01

A development was conducted to investigate the performance of an open chamber gas engine with pilot fuel for ignition source. Experiments were conducted by using a gas engine equipped with a common-rail injection system. Main gas fuel is supplied to the engine cylinder, and then a small quantity of diesel fuel (approximately 1 % of total fuel energy input) was injected into the main chamber for ignition. The single cylinder prototype gas engine has demonstrated superior performance, such as, a shaft-end thermal efficiency of 36.7% with NO{sub x} level of 0.4 g/kW-h, which equals those of conventional spark ignited pre-chamber lean burn gas engines. For the next step, the multi-cylinder gas engine has been developed. That has 138 mm bore, 142 mm stroke, V8 configuration and 229 kW engine output 1500 rpm. This engine can also run with only diesel fuel for Standby-Power-Concurrent Co-generation. (authors)

Multi-Stage Selective Catalytic Reduction of NOx in Lean-Burn Engine Exhaust

National Research Council Canada - National Science Library

Penetrante, B

1997-01-01

.... A plasma can also be used to oxidize NO to NO2. This paper compares the multi-stage catalytic scheme with the plasma-assisted catalytic scheme for reduction of NOx in lean-burn engine exhausts. The advantages of plasma oxidation over catalytic oxidation are presented.

Application of Hydrogen Assisted Lean Operation to Natural Gas-Fueled Reciprocating Engines (HALO)

Energy Technology Data Exchange (ETDEWEB)

Chad Smutzer

2006-01-01

Two key challenges facing Natural Gas Engines used for cogeneration purposes are spark plug life and high NOx emissions. Using Hydrogen Assisted Lean Operation (HALO), these two keys issues are simultaneously addressed. HALO operation, as demonstrated in this project, allows stable engine operation to be achieved at ultra-lean (relative air/fuel ratios of 2) conditions, which virtually eliminates NOx production. NOx values of 10 ppm (0.07 g/bhp-hr NO) for 8% (LHV H2/LHV CH4) supplementation at an exhaust O2 level of 10% were demonstrated, which is a 98% NOx emissions reduction compared to the leanest unsupplemented operating condition. Spark ignition energy reduction (which will increase ignition system life) was carried out at an oxygen level of 9%, leading to a NOx emission level of 28 ppm (0.13 g/bhp-hr NO). The spark ignition energy reduction testing found that spark energy could be reduced 22% (from 151 mJ supplied to the coil) with 13% (LHV H2/LHV CH4) hydrogen supplementation, and even further reduced 27% with 17% hydrogen supplementation, with no reportable effect on NOx emissions for these conditions and with stable engine torque output. Another important result is that the combustion duration was shown to be only a function of hydrogen supplementation, not a function of ignition energy (until the ignitability limit was reached). The next logical step leading from these promising results is to see how much the spark energy reduction translates into increase in spark plug life, which may be accomplished by durability testing.

Advanced Natural Gas Reciprocating Engine(s)

Energy Technology Data Exchange (ETDEWEB)

Kwok, Doris; Boucher, Cheryl

2009-09-30

Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

Energy Efficient Thermal Management for Natural Gas Engine Aftertreatment via Active Flow Control

Energy Technology Data Exchange (ETDEWEB)

David K. Irick; Ke Nguyen; Vitacheslav Naoumov; Doug Ferguson

2006-04-01

The project is focused on the development of an energy efficient aftertreatment system capable of reducing NOx and methane by 90% from lean-burn natural gas engines by applying active exhaust flow control. Compared to conventional passive flow-through reactors, the proposed scheme cuts supplemental energy by 50%-70%. The system consists of a Lean NOx Trap (LNT) system and an oxidation catalyst. Through alternating flow control, a major amount of engine exhaust flows through a large portion of the LNT system in the absorption mode, while a small amount of exhaust goes through a small portion of the LNT system in the regeneration or desulfurization mode. By periodically reversing the exhaust gas flow through the oxidation catalyst, a higher temperature profile is maintained in the catalyst bed resulting in greater efficiency of the oxidation catalyst at lower exhaust temperatures. The project involves conceptual design, theoretical analysis, computer simulation, prototype fabrication, and empirical studies. This report details the progress during the first twelve months of the project. The primary activities have been to develop the bench flow reactor system, develop the computer simulation and modeling of the reverse-flow oxidation catalyst, install the engine into the test cell, and begin design of the LNT system.

Characterization of biomass producer gas as fuel for stationary gas engines in combined heat and power production

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper

2008-01-01

The aim of this project has been the characterization of biomass producer gas as a fuel for stationary gas engines in heat and power production. More than 3200 hours of gas engine operation, with producer gas as fuel, has been conducted at the biomass gasification combined heat and power (CHP...... different measuring methods. Likewise, no particles were detected in the gas. Considerable amounts of NH3 were measured in the produced gas.An analysis of engine operation at varying load has been carried out. Standard emissions, load and efficiency have been measured at varying operating conditions ranging...... from 50% to 90% load. Biomass producer gas is an excellent lean burn engine fuel: Operation of a natural aspirated engine has been achieved for 1.2...

Investigation on the lean combustion performance of a hydrogen-enriched n-butanol engine

International Nuclear Information System (INIS)

Zhang, Bo; Ji, Changwei; Wang, Shuofeng

2017-01-01

Highlights: • H_2 addition avails improving thermal efficiency of n-butanol engines. • Lean burn limit of n-butanol engine is extended by H_2 addition. • H_2 addition shortens the n-butanol engine combustion duration. • HC and CO from the n-butanol engine are decreased by H_2 addition. - Abstract: n-Butanol is a feasible fuel candidate for spark-ignition engines. The current paper carried out an experiment to explore effects of hydrogen addition on further improving the performance of a n-butanol engine under the part load and lean conditions. Within the test, the engine intake pressure and speed were respectively kept at 61.5 kPa and 1400 rpm. The volumetric fractions of hydrogen in the total intake gas (hydrogen + air) were constrained at 0 and 3%, respectively. Under a certain hydrogen blending level, the global excess air ratio of in-cylinder charge which was changed from the stoichiometric to near the lean burn limit was adjusted by varying the n-butanol injection duration. The experimental results confirmed that the brake thermal efficiency was heightened and the lean burn limit was extended after the hydrogen addition. Besides, compared with the pure n-butanol combustion, the hydrogen enrichment enables the engine to gain dropped ignition delay and rapid combustion duration. Moreover, CO and HC from the pure n-butanol engine were reduced by the hydrogen addition. NOx were generally reduced when the excess air ratio was raised. This suggested that NOx from the hydrogen-enriched butanol engine could also be controlled by lean combustion.

Experimental and modeling study of hydrogen/syngas production and particulate emissions from a natural gas-fueled partial oxidation engine

International Nuclear Information System (INIS)

McMillian, Michael H.; Lawson, Seth A.

2006-01-01

In this study, a combustion model was first applied to conditions representing varying compression ratios and equivalence ratios to investigate engine exhaust composition from partial oxidation (POX) of natural gas in reciprocating engines. The model was experimentally validated over a range of equivalence ratios from 1.3 to 1.6 with a spark-ignited single cylinder engine fueled by natural gas. The modeling results matched well with engine gaseous emission data over the experimental range. The model was also extended to higher equivalence ratios to predict H 2 and CO production at engine conditions and stoichiometries representative of homogeneous charge compression ignition (HCCI) engine operation. Secondly, over the same experimental range of equivalence ratios, particulate samples were taken to determine both total particulate mass production (g/hph) via gravimetric measurement as well as particle size distribution and loading via a scanning mobility particle sizer (SMPS). While experiments indicate hydrogen yields up to 11% using spark ignition (SI), modeling results indicate that greater than 20% H 2 yield may be possible in HCCI operation. Over the experimental range, rich-burn particulate matter (PM) production is no greater than that from typical lean-burn operation. Finally, an energy balance was performed over the range of engine experimental operation. (author)

Detailed characterization of particulate matter emitted by lean-burn gasoline direct injection engine

Energy Technology Data Exchange (ETDEWEB)

Zelenyuk, Alla [Pacific Northwest National Laboratory, Richland, WA, USA; Wilson, Jacqueline [Pacific Northwest National Laboratory, Richland, WA, USA; Imre, Dan [Imre Consulting, Richland, WA, USA; Stewart, Mark [Pacific Northwest National Laboratory, Richland, WA, USA; Muntean, George [Pacific Northwest National Laboratory, Richland, WA, USA; Storey, John [Oak Ridge National Laboratory, Knoxville, TN, USA; Prikhodko, Vitaly [Oak Ridge National Laboratory, Knoxville, TN, USA; Lewis, Samuel [Oak Ridge National Laboratory, Knoxville, TN, USA; Eibl, Mary [Oak Ridge National Laboratory, Knoxville, TN, USA; Parks, Jim [Oak Ridge National Laboratory, Knoxville, TN, USA

2016-11-10

This study presents detailed characterization of the chemical and physical properties of PM emitted by a 2.0L BMW lean-burn turbocharged GDI engine operated under a number of combustion strategies that include lean homogeneous, lean stratified, stoichiometric, and fuel rich conditions. We characterized PM number concentrations, size distributions, and the size, mass, compositions, and effective density of fractal and compact individual exhaust particles. For the fractal particles, these measurements yielded fractal dimension, average diameter of primary spherules, and number of spherules, void fraction, and dynamic shape factors as function of particle size. Overall, the PM properties were shown to vary significantly with engine operation condition. Lean stratified operation yielded the most diesel-like size distribution and the largest PM number and mass concentrations, with nearly all particles being fractal agglomerates composed of elemental carbon with small amounts of ash and organics. In contrast, stoichiometric operation yielded a larger fraction of ash particles, especially at low speed and low load. Three distinct forms of ash particles were observed, with their fractions strongly dependent on engine operating conditions: sub-50 nm ash particles, abundant at low speed and low load, ash-containing fractal particles, and large compact ash particles that significantly contribute to PM mass loadings

IGNITION IMPROVEMENT OF LEAN NATURAL GAS MIXTURES

Energy Technology Data Exchange (ETDEWEB)

Jason M. Keith

2005-02-01

This report describes work performed during a thirty month project which involves the production of dimethyl ether (DME) on-site for use as an ignition-improving additive in a compression-ignition natural gas engine. A single cylinder spark ignition engine was converted to compression ignition operation. The engine was then fully instrumented with a cylinder pressure transducer, crank shaft position sensor, airflow meter, natural gas mass flow sensor, and an exhaust temperature sensor. Finally, the engine was interfaced with a control system for pilot injection of DME. The engine testing is currently in progress. In addition, a one-pass process to form DME from natural gas was simulated with chemical processing software. Natural gas is reformed to synthesis gas (a mixture of hydrogen and carbon monoxide), converted into methanol, and finally to DME in three steps. Of additional benefit to the internal combustion engine, the offgas from the pilot process can be mixed with the main natural gas charge and is expected to improve engine performance. Furthermore, a one-pass pilot facility was constructed to produce 3.7 liters/hour (0.98 gallons/hour) DME from methanol in order to characterize the effluent DME solution and determine suitability for engine use. Successful production of DME led to an economic estimate of completing a full natural gas-to-DME pilot process. Additional experimental work in constructing a synthesis gas to methanol reactor is in progress. The overall recommendation from this work is that natural gas to DME is not a suitable pathway to improved natural gas engine performance. The major reasons are difficulties in handling DME for pilot injection and the large capital costs associated with DME production from natural gas.

The relative effects of fuel concentration, residual-gas fraction, gas motion, spark energy and heat losses to the electrodes on flame-kernel development in a lean-burn spark ignition engine

Energy Technology Data Exchange (ETDEWEB)

Aleiferis, P.G.; Taylor, A.M.K.P. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Mechanical Engineering; Ishii, K. [Honda International Technical School, Saitama (Japan); Urata, Y. [Honda R and D Co., Ltd., Tochigi (Japan). Tochigi R and D Centre

2004-04-01

The potential of lean combustion for the reduction in exhaust emissions and fuel consumption in spark ignition engines has long been established. However, the operating range of lean-burn spark ignition engines is limited by the level of cyclic variability in the early-flame development stage that typically corresponds to the 0-5 per cent mass fraction burned duration. In the current study, the cyclic variations in early flame development were investigated in an optical stratified-charge spark ignition engine at conditions close to stoichiometry [air-to-fuel ratio (A/F) = 15] and to the lean limit of stable operation (A/F = 22). Flame images were acquired through either a pentroof window ('tumble plane' of view) or the piston crown ('swirl plane' of view) and these were processed to calculate the intra-cycle flame-kernel radius evolution. In order to quantify the relative effects of local fuel concentration, gas motion, spark-energy release and heat losses to the electrodes on the flame-kernel growth rate, a zero-dimensional flame-kernel growth model, in conjunction with a one-dimensional spark ignition model, was employed. Comparison of the calculated flame-radius evolutions with the experimental data suggested that a variation in A/F around the spark plug of {delta}(A/F) {approx} 4 or, in terms of equivalence ratio {phi}, a variation in {delta}{phi} {approx} 0.15 at most was large enough to account for 100 per cent of the observed cyclic variability in flame-kernel radius. A variation in the residual-gas fraction of about 20 per cent around the mean was found to account for up to 30 per cent of the variability in flame-kernel radius at the timing of 5 per cent mass fraction burned. The individual effect of 20 per cent variations in the 'mean' in-cylinder velocity at the spark plug at ignition timing was found to account for no more than 20 per cent of the measured cyclic variability in flame kernel radius. An individual effect of

Load compensation in a lean burn natural gas vehicle

Science.gov (United States)

Gangopadhyay, Anupam

A new multivariable PI tuning technique is developed in this research that is primarily developed for regulation purposes. Design guidelines are developed based on closed-loop stability. The new multivariable design is applied in a natural gas vehicle to combine idle and A/F ratio control loops. This results in better recovery during low idle operation of a vehicle under external step torques. A powertrain model of a natural gas engine is developed and validated for steady-state and transient operation. The nonlinear model has three states: engine speed, intake manifold pressure and fuel fraction in the intake manifold. The model includes the effect of fuel partial pressure in the intake manifold filling and emptying dynamics. Due to the inclusion of fuel fraction as a state, fuel flow rate into the cylinders is also accurately modeled. A linear system identification is performed on the nonlinear model. The linear model structure is predicted analytically from the nonlinear model and the coefficients of the predicted transfer function are shown to be functions of key physical parameters in the plant. Simulations of linear system and model parameter identification is shown to converge to the predicted values of the model coefficients. The multivariable controller developed in this research could be designed in an algebraic fashion once the plant model is known. It is thus possible to implement the multivariable PI design in an adaptive fashion combining the controller with identified plant model on-line. This will result in a self-tuning regulator (STR) type controller where the underlying design criteria is the multivariable tuning technique designed in this research.

Temperature and air-fuel ratio dependent specific heat ratio functions for lean burned and unburned mixture

International Nuclear Information System (INIS)

Ceviz, M.A.; Kaymaz, I.

2005-01-01

The most important thermodynamic property used in heat release calculations for engines is the specific heat ratio. The functions proposed in the literature for the specific heat ratio are temperature dependent and apply at or near stoichiometric air-fuel ratios. However, the specific heat ratio is also influenced by the gas composition in the engine cylinder and especially becomes important for lean combustion engines. In this study, temperature and air-fuel ratio dependent specific heat ratio functions were derived to minimize the error by using an equilibrium combustion model for burned and unburned mixtures separately. After the error analysis between the equilibrium combustion model and the derived functions is presented, the results of the global specific heat ratio function, as varying with mass fraction burned, were compared with the proposed functions in the literature. The results of the study showed that the derived functions are more feasible at lean operating conditions of a spark ignition engine

Multi-stage selective catalytic reduction of NOx in lean burn engine exhaust

Energy Technology Data Exchange (ETDEWEB)

Penetrante, B.M.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

1997-12-31

Many studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. Some effort has been devoted to separating the oxidative and reductive functions of the catalyst in a multi-stage system. This method works fine for systems that require hydrocarbon addition. The hydrocarbon has to be injected between the NO oxidation catalyst and the NO{sub 2} reduction catalyst; otherwise, the first-stage oxidation catalyst will also oxidize the hydrocarbon and decrease its effectiveness as a reductant. The multi-stage catalytic scheme is appropriate for diesel engine exhausts since they contain insufficient hydrocarbons for SCR, and the hydrocarbons can be added at the desired location. For lean-burn gasoline engine exhausts, the hydrocarbons already present in the exhausts will make it necessary to find an oxidation catalyst that can oxidize NO to NO{sub 2} but not oxidize the hydrocarbon. A plasma can also be used to oxidize NO to NO{sub 2}. Plasma oxidation has several advantages over catalytic oxidation. Plasma-assisted catalysis can work well for both diesel engine and lean-burn gasoline engine exhausts. This is because the plasma can oxidize NO in the presence of hydrocarbons without degrading the effectiveness of the hydrocarbon as a reductant for SCR. In the plasma, the hydrocarbon enhances the oxidation of NO, minimizes the electrical energy requirement, and prevents the oxidation of SO{sub 2}. This paper discusses the use of multi-stage systems for selective catalytic reduction of NO{sub x}. The multi-stage catalytic scheme is compared to the plasma-assisted catalytic scheme.

Development II of ion current combustion control system. Application to the lean burn system of the micro vehicle engine; Ion denryu wo mochiita nensho seigyo system no kaihatsu. 2. Keijidosha engine wo mochiita lean burn eno oyo

Energy Technology Data Exchange (ETDEWEB)

Iida, T; Asano, M; Kajitani, M; Kuma, t; Morinaga, Y [Daihatsu Motor Co. Ltd., Osaka (Japan)

1997-10-01

The lean bum engine has not been introduced into the micro vehicle so far because of the low cost requirement and small displacement, in spite of it is one of the effective solutions which increase the fuel economy. By the way, we had already reported in the former paper that we developed the ion current combustion control system the architecture of which is cheaper than the other system. In this paper, we described the way how the above system is applied to the lean burn system of the micro vehicle engine and also we reported the gain of fuel economy and the exhaust emission level. 5 refs., 11 figs., 2 tabs.

Lean mixture engine testing and evaluation program. [for automobile engine pollution and fuel performances

Science.gov (United States)

Dowdy, M. W.; Hoehn, F. W.; Griffin, D. C.

1975-01-01

Experimental results for fuel consumption and emissions are presented for a 350 CID (5.7 liter) Chevrolet V-8 engine modified for lean operation with gasoline. The lean burn engine achieved peak thermal efficiency at an equivalence ratio of 0.75 and a spark advance of 60 deg BTDC. At this condition the lean burn engine demonstrated a 10% reduction in brake specific fuel consumption compared with the stock engine; however, NOx and hydrocarbon emissions were higher. With the use of spark retard and/or slightly lower equivalence ratios, the NOx emissions performance of the stock engine was matched while showing a 6% reduction in brake specific fuel consumption. Hydrocarbon emissions exceeded the stock values in all cases. Diagnostic data indicate that lean performance in the engine configuration tested is limited by ignition delay, cycle-to-cycle pressure variations, and cylinder-to-cylinder distribution.

Performance evaluation of an advanced air-fuel ratio controller on a stationary, rich-burn natural gas engine

Science.gov (United States)

Kochuparampil, Roshan Joseph

The advent of an era of abundant natural gas is making it an increasingly economical fuel source against incumbents such as crude oil and coal, in end-use sectors such as power generation, transportation and industrial chemical production, while also offering significant environmental benefits over these incumbents. Equipment manufacturers, in turn, are responding to widespread demand for power plants optimized for operation with natural gas. In several applications such as distributed power generation, gas transmission, and water pumping, stationary, spark-ignited, natural gas fueled internal combustion engines (ICEs) are the power plant of choice (over turbines) owing to their lower equipment and operational costs, higher thermal efficiencies across a wide load range, and the flexibility afforded to end-users when building fine-resolution horsepower topologies: modular size increments ranging from 100 kW -- 2 MW per ICE power plant compared to 2 -- 5 MW per turbine power plant. Under the U.S. Environment Protection Agency's (EPA) New Source Performance Standards (NSPS) and Reciprocating Internal Combustion Engine National Emission Standards for Hazardous Air Pollutants (RICE NESHAP) air quality regulations, these natural gas power plants are required to comply with stringent emission limits, with several states mandating even stricter emissions norms. In the case of rich-burn or stoichiometric natural gas ICEs, very high levels of sustained emissions reduction can be achieved through exhaust after-treatment that utilizes Non Selective Catalyst Reduction (NSCR) systems. The primary operational constraint with these systems is the tight air-fuel ratio (AFR) window of operation that needs to be maintained if the NSCR system is to achieve simultaneous reduction of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), volatile organic compounds (VOCs), and formaldehyde (CH 2O). Most commercially available AFR controllers utilizing lambda (oxygen

Air-fuel ratio control of a lean burn Si engine using fuzzy self tuning method

International Nuclear Information System (INIS)

Akhlaghi, M.; Bakhtiari Nejad, F.; Azadi, S.

2000-01-01

Reducing the exhaust emission of an spark ignition engine by means of engine modifications requires consideration of the effects of these modifications on the variations of crankshaft torque and the engine roughness respectively. Only if the roughness does not exceed a certain level the vehicle do not begin to surge. This paper presents a method for controlling the air-fuel ratio for a lean burn engine. Fuzzy rules and reasoning are utilized on-line to determine the control parameters. The main advantages of this method are simple structure and robust performance in a wide range of operating conditions. A non-linear model of an Si engine with the engine torque irregularity simulation is used in this study

Catalytic removal of methane and NO{sub x} in lean-burn natural-gas engine exhaust; Elimination par catalyse du methane et des NO{sub x} dans les echappements de moteur au gaz naturel a basse combustion

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, H.; Satokawa, S.; Yahagi, M.; Yamaseki, K.; Hoshi, F.; Uchida, H.; Yokota, H. [Tokyo Gas Co., Ltd. (Japan)

2000-07-01

We have developed a new catalytic system to reduce the emissions of hydrocarbons, carbon monoxide (CO), and nitrogen oxides (NO{sub x}) contained in the exhaust gases from a lean-burn natural-gas engine. Catalytic oxidation of unburned hydrocarbons and CO in the exhaust has been studied for noble metals supported on alumina. (1) A low-loading catalyst comprising platinum supported on alumina (Pt/alumina) was efficient for the oxidation of CO and hydrocarbons without methane. The CO conversions were maintained at more than 98 % for 20,000 hours over the Pt/alumina. (2) A catalyst comprising platinum and palladium supported on alumina (Pt-Pd/alumina) exhibited higher levels of oxidation of hydrocarbons (including methane) than a catalyst comprising only palladium supported on alumina (Pd/alumina). Its oxidation also lasted longer. The combined effects of the platinum and palladium metals achieved high sulfur dioxide resistance. Increasing the palladium content in the Pt-Pd/alumina catalyst increased the level of oxidation and extended the lifetime of the catalyst. (3) A catalyst comprising silver supported on alumina (Ag/alumina) was effective at reducing the amount of NO{sub X} by using the unburned hydrocarbons in the exhaust gas. The NO{sub x} conversions over Ag/alumina were maintained at more than 30 % for 3,500 hours. We describe a total clean-up system consisting of a Ag/alumina catalyst and a Pt-Pd/alumina catalyst in series on the exhaust gas stream. (authors)

A predictive model of natural gas mixture combustion in internal combustion engines

Directory of Open Access Journals (Sweden)

Henry Espinoza

2007-05-01

Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

Attempt of lean burn of a 4 cycle gasoline engine by the aid of low pressure air assisted in-cylinder injection; Tonai kuki nenryo funsha ni yoru lean burn no kokoromi

Energy Technology Data Exchange (ETDEWEB)

Hatakeyama, S; Kondo, M; Sekiya, Y; Murayama, T [Hokkaido Automotive Engineering College, Hokkaido (Japan)

1997-10-01

Comparable performance and exhaust emission with conventional carburetor was obtained by a low Pressure air assisted in-cylinder injection system. And lean burn of idling and light load operation till A/F=70 was realized by installing a spark Plug and a reed type injection nozzle in a divided combustion chambaer of a 4 cycle gasoline engine. 2 refs., 10 figs.

Optimization of combustion chamber geometry for natural gas engines with diesel micro-pilot-induced ignition

International Nuclear Information System (INIS)

Wang, Bin; Li, Tie; Ge, Linlin; Ogawa, Hideyuki

2016-01-01

Highlights: • Combustion chamber geometry is optimized to reduce the HC/CO emissions. • CFD model is calibrated against the spray visualization and engine bench test data. • Design space is explored by the multi-objective NSGA-II with Kriging meta-model. • HC and CO emissions are respectively reduced by 56.47% and 33.55%. - Abstract: Smokeless, low nitrogen oxides (NOx), and high thermal efficiency have been achieved through the lean-burn concept for natural gas engine with diesel micro-pilot-induced ignition (MPII). However, the combustion chamber is usually not specialized for natural gas combustion, and increases in the unburned hydrocarbon (HC) and carbon monoxide (CO) emissions are still a challenge for this type of engines. This paper describes optimization of the combustion chamber geometry to reduce the HC and CO emissions and improve the combustion efficiency in the MPII natural gas engine. The 3-D computational fluid dynamics (CFD) simulation model coupled with a chemical reaction mechanism is described. The temporal development of the short-pulsed diesel spray in a high pressure constant-volume vessel is measured and used to calibrate the spray model in the CFD simulation. The simulation models are validated by the experimental data of the in-cylinder pressure trace, apparent heat release rate (AHRR) and exhaust gas emissions from a single-cylinder MPII natural gas engine. To generate the various combustion chamber geometries, the bowl outline is parameterized by the two cubic Bezier curves while keeping the compression ratio constant. The available design space is explored by the multi-objective non-dominated sorting genetic algorithm II (NSGA-II) with Kriging-based meta-model. With the optimization, the HC and CO emissions are reduced by 56.47% and 33.55%, respectively, while the NOx emissions, the maximum rate of pressure rise and the gross indicated thermal efficiency that are employed as the constraints are slightly improved. Finally, the

Technology for emission control in internal combustion engines; Kakushu nainen kikan ni okeru hai gas joka gijutsu

Energy Technology Data Exchange (ETDEWEB)

Shioji, M. [Kyoto University, Kyoto (Japan)

1998-09-01

Described herein are emission control technology and exhaust gas cleaning measures for internal combustion engines. Gas turbines burn relatively high-quality fuels, such as natural gas, kerosene, diesel oil and gas oil, where the major concerns are to reduce NOx and dust emissions. The NOx abatement techniques fall into two general categories; wet processes which inject water or steam, and dry processes which depend on improved combustion. Power generation and cogeneration which burn natural gas adopt lean, premixed combustion and two-stage combustion as the major approaches. Low-speed, large-size diesel engines, which realize very high thermal efficiency, discharge high concentrations of NOx. Delayed fuel injection timing is the most easy NOx abatement technique to meet the related regulations, but is accompanied by decreased fuel economy. Use of water-emulsified fuel, water layer injection and multi-port injection can reduce NOx emissions without decreasing fuel economy, depending on optimization methods adopted. Automobile gasoline engines are required to further clean exhaust gases by catalystic systems. 9 refs., 10 figs., 6 tabs.

Study of cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends

Energy Technology Data Exchange (ETDEWEB)

Wang, Jinhua; Chen, Hao; Liu, Bing; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2008-09-15

Cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends with hydrogen volumetric fraction of 0%, 12%, 23%, 30% and 40% were studied. The effect of hydrogen addition on cycle-by-cycle variations of the natural gas engine was analyzed. The results showed that the peak cylinder pressure, the maximum rate of pressure rise and the indicated mean effective pressure increased and their corresponding cycle-by-cycle variations decreased with the increase of hydrogen fraction at lean mixture operation. The interdependency between the combustion parameters and the corresponding crank angle tended to be strongly correlated with the increase of hydrogen fraction under lean mixture operation. Coefficient of variation of the indicated mean effective pressure gave a low level and is slightly influenced by hydrogen addition under the stoichiometric and relatively rich mixture operation while it decreased remarkably with the increase of hydrogen fraction under the lean mixture operation. The excessive air ratio at CoV{sub imep} = 10% extended to the leaner mixture side with the increase of hydrogen fraction and this indicated that the engine lean operating limit could be extended with hydrogen addition. (author)

The Role of Post Flame Oxidation on the UHC Emission for Combustion of Natural Gas and Hydrogen Containing fuels

DEFF Research Database (Denmark)

Jensen, Torben Kvist; Schramm, Jesper

2003-01-01

In-cylinder post flame oxidation of unburned hydro-carbons from crevices in a lean burn spark ignition engine has been examined for natural gas and mixtures of natural gas and a hydrogen containing producer gas. For this purpose a model was developed to describe the mixing of cold unburned...... during in-cylinder post oxidation. The Arrhenius parameters were determined using the reaction mechanism, which gave the prediction of the results from the combustion reactor experiments. The investigation showed that addition of producer gas to natural gas promotes the in-cylinder post oxidation...... significantly. Furthermore it was found that the cyclic variation in the post oxidation is reduced by addition of producer gas to natural gas....

Plasma-assisted heterogeneous catalysis for NOx reduction in lean-burn engine exhaust

Energy Technology Data Exchange (ETDEWEB)

Penetrante, B.M.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States); Wan, C.Z.; Rice, G.W.; Voss, K.E. [Engelhard Corp., Iselin, NJ (United States)

1997-12-31

This paper discusses the combination of a plasma with a catalyst to improve the reduction of NO{sub x} under lean-burn conditions. The authors have been investigating the effects of a plasma on the NO{sub x} reduction activity and temperature operating window of various catalytic materials. One of the goals is to develop a fundamental understanding of the interaction between the gas-phase plasma chemistry and the heterogeneous chemistry on the catalyst surface. The authors have observed that plasma assisted heterogeneous catalysis can facilitate NO{sub x} reduction under conditions that normally make it difficult for either the plasma or the catalyst to function by itself. By systematically varying the plasma electrode and catalyst configuration, they have been able to elucidate the process by which the plasma chemistry affects the chemical reduction of NO{sub x} on the catalyst surface. They have discovered that the main effect of the plasma is to induce the gas-phase oxidation of NO to NO{sub 21}. The reduction of NO{sub x} to N{sub 2} is then accomplished by heterogeneous reaction of O with activated hydrocarbons on the catalyst surface. The use of a plasma opens the opportunity for a new class of catalysts that are potentially more durable, more active, more selective and more sulfur-tolerant compared to conventional lean-NO{sub x} catalysts.

Lean-rich axial stage combustion in a can-annular gas turbine engine

Science.gov (United States)

Laster, Walter R.; Szedlacsek, Peter

2016-06-14

An apparatus and method for lean/rich combustion in a gas turbine engine (10), which includes a combustor (12), a transition (14) and a combustor extender (16) that is positioned between the combustor (12) and the transition (14) to connect the combustor (12) to the transition (14). Openings (18) are formed along an outer surface (20) of the combustor extender (16). The gas turbine (10) also includes a fuel manifold (28) to extend along the outer surface (20) of the combustor extender (16), with fuel nozzles (30) to align with the respective openings (18). A method (200) for axial stage combustion in the gas turbine engine (10) is also presented.

Performance of a hydrogen-enriched ethanol engine at unthrottled and lean conditions

International Nuclear Information System (INIS)

Zhang, Bo; Ji, Changwei; Wang, Shuofeng

2016-01-01

Highlights: • H_2 addition eased cyclic variation of ethanol engine at unthrottled condition. • H_2-blended ethanol engine gains better efficiency at lean conditions. • Bmep of H_2-blended ethanol engine could be controlled by lean burning. • H_2 addition results in reduced exhaust loss and HC emissions. - Abstract: Concerning the throttling loss under part load conditions, it is feasible to further improve the engine thermal efficiency through operating the engine under the unthrottled condition and controlling its load by changing the excess air ratio. However, the narrow flammability of ethanol may lead the ethanol engine to encounter high cyclic variations under unthrottled and lean conditions. The addition of hydrogen is potentially helpful for solving this problem. In this test, the engine was run under an speed of 1400 rpm and unthrottled conditions. The hydrogen volume fractions in the intake were respectively kept at 0% and 3%. For a given hydrogen blending level, the ethanol flow rate was reduced to enable the engine to run under lean conditions. The results showed that the engine efficiency was improved with the blending of hydrogen. The highest thermal efficiency was improved by 6.07% after blending 3% hydrogen to the intake air. The addition of hydrogen could increase the engine torque output at lean conditions. Both cooling and exhaust losses were decreased after the hydrogen enrichment while adopting the lean combustion strategy. The hydrogen addition contributed to the extended lean burn limit and decreased cyclic variation under lean conditions. HC and CO emissions were decreased whereas NOx emissions were increased after the blending of hydrogen.

Methane Emissions from Leak and Loss Audits of Natural Gas Compressor Stations and Storage Facilities.

Science.gov (United States)

Johnson, Derek R; Covington, April N; Clark, Nigel N

2015-07-07

As part of the Environmental Defense Fund's Barnett Coordinated Campaign, researchers completed leak and loss audits for methane emissions at three natural gas compressor stations and two natural gas storage facilities. Researchers employed microdilution high-volume sampling systems in conjunction with in situ methane analyzers, bag samples, and Fourier transform infrared analyzers for emissions rate quantification. All sites had a combined total methane emissions rate of 94.2 kg/h, yet only 12% of the emissions total resulted from leaks. Methane slip from exhausts represented 44% of the total emissions. Remaining methane emissions were attributed to losses from pneumatic actuators and controls, engine crankcases, compressor packing vents, wet seal vents, and slop tanks. Measured values were compared with those reported in literature. Exhaust methane emissions were lower than emissions factor estimates for engine exhausts, but when combined with crankcase emissions, measured values were 11.4% lower than predicted by AP-42 as applicable to emissions factors for four-stroke, lean-burn engines. Average measured wet seal emissions were 3.5 times higher than GRI values but 14 times lower than those reported by Allen et al. Reciprocating compressor packing vent emissions were 39 times higher than values reported by GRI, but about half of values reported by Allen et al. Though the data set was small, researchers have suggested a method to estimate site-wide emissions factors for those powered by four-stroke, lean-burn engines based on fuel consumption and site throughput.

Effects of spark plug configuration on combustion and emission characteristics of a LPG fuelled lean burn SI engine

Science.gov (United States)

Ravi, K.; Khan, Manazir Ahmed; Pradeep Bhasker, J.; Porpatham, E.

2017-11-01

Introduction of technological innovation in automotive engines in reducing pollution and increasing efficiency have been under contemplation. Gaseous fuels have proved to be a promising way to reduce emissions in Spark Ignition (SI) engines. In particular, LPG settled to be a favourable fuel for SI engines because of their higher hydrogen to carbon ratio, octane rating and lower emissions. Wide ignition limits and efficient combustion characteristics make LPG suitable for lean burn operation. But lean combustion technology has certain drawbacks like poor flame propagation, cyclic variations etc. Based on copious research it was found that location, types and number of spark plug significantly influence in reducing cyclic variations. In this work the influence of single and dual spark plugs of conventional and surface discharge electrode type were analysed. Dual surface discharge electrode spark plug enhanced the brake thermal efficiency and greatly reduced the cyclic variations. The experimental results show that rate of heat release and pressure rise was more and combustion duration was shortened in this configuration. On the emissions front, the NOx emission has increased whereas HC and CO emissions were reduced under lean condition.

Development and test of combustion chamber for Stirling engine heated by natural gas

Science.gov (United States)

Li, Tie; Song, Xiange; Gui, Xiaohong; Tang, Dawei; Li, Zhigang; Cao, Wenyu

2014-04-01

The combustion chamber is an important component for the Stirling engine heated by natural gas. In the paper, we develop a combustion chamber for the Stirling engine which aims to generate 3˜5 kWe electric power. The combustion chamber includes three main components: combustion module, heat exchange cavity and thermal head. Its feature is that the structure can divide "combustion" process and "heat transfer" process into two apparent individual steps and make them happen one by one. Since natural gas can mix with air fully before burning, the combustion process can be easily completed without the second wind. The flame can avoid contacting the thermal head of Stirling engine, and the temperature fields can be easily controlled. The designed combustion chamber is manufactured and its performance is tested by an experiment which includes two steps. The experimental result of the first step proves that the mixture of air and natural gas can be easily ignited and the flame burns stably. In the second step of experiment, the combustion heat flux can reach 20 kW, and the energy utilization efficiency of thermal head has exceeded 0.5. These test results show that the thermal performance of combustion chamber has reached the design goal. The designed combustion chamber can be applied to a real Stirling engine heated by natural gas which is to generate 3˜5 kWe electric power.

Low-Load Limit in a Diesel-Ignited Gas Engine

Directory of Open Access Journals (Sweden)

Richard Hutter

2017-09-01

Full Text Available The lean-burn capability of the Diesel-ignited gas engine combined with its potential for high efficiency and low CO 2 emissions makes this engine concept one of the most promising alternative fuel converters for passenger cars. Instead of using a spark plug, the ignition relies on the compression-ignited Diesel fuel providing ignition centers for the homogeneous air-gas mixture. In this study the amount of Diesel is reduced to the minimum amount required for the desired ignition. The low-load operation of such an engine is known to be challenging, as hydrocarbon (HC emissions rise. The objective of this study is to develop optimal low-load operation strategies for the input variables equivalence ratio and exhaust gas recirculation (EGR rate. A physical engine model helps to investigate three important limitations, namely maximum acceptable HC emissions, minimal CO 2 reduction, and minimal exhaust gas temperature. An important finding is the fact that the high HC emissions under low-load and lean conditions are a consequence of the inability to raise the gas equivalence ratio resulting in a poor flame propagation. The simulations on the various low-load strategies reveal the conflicting demand of lean combustion with low CO 2 emissions and stoichiometric operation with low HC emissions, as well as the minimal feasible dual-fuel load of 3.2 bar brake mean effective pressure.

Lean hydrous and anhydrous bioethanol combustion in spark ignition engine at idle

International Nuclear Information System (INIS)

Chuepeng, Sathaporn; Srisuwan, Sudecha; Tongroon, Manida

2016-01-01

Highlights: • Anhydrous ethanol burns fastest in uncalibrated engine at equal equivalence ratio. • The leaner hydrous ethanol combustion tends to elevate the COV in imep. • Hydrous ethanol consumption was 10% greater than anhydrous ethanol at ϕ = 0.67 limit. • Optimizing alternative fuel engine at idle for stability and emission is suggested. - Abstract: The applications of anhydrous bioethanol to substitute or replace gasoline fuel have shown to attain benefits in terms of engine thermal efficiency, power output and exhaust emissions from spark ignition engines. A hydrous bioethanol has also been gained more attention due to its energy and cost effectiveness. The main aim of this work is to minimize fuel quantity injected to the intake ports of a four-cylinder engine under idle condition. The engine running with hydrous ethanol undergoes within lean-burn condition as its combustion stability is analyzed using an engine indicating system. Coefficient of variation in indicated mean effective pressure is an indicator for combustion stability with hydrocarbon and carbon monoxide emission monitoring as a supplement. Anhydrous ethanol burns faster than hydrous ethanol and gasoline in the uncalibrated engine at the same fuel-to-air equivalence ratio under idle condition. The leaner hydrous ethanol combustion tends to elevate the coefficient of variation in indicated mean effective pressure. The experimental results have found that the engine consumes greater hydrous ethanol by 10% on mass basis compared with those of anhydrous ethanol at the lean limit of fuel-to-air equivalence ratio of 0.67. The results of exhaust gas analysis were compared with those predicted by chemical equilibrium analysis of the fuel-air combustion; the resemble trends were found. Calibrating the alternative fueled engine for fuel injection quantity should be accomplished at idle with combustion stability and emissions optimization.

The Role of Post Flame Oxidation on the UHC Emission for Combustion of Natural Gas and Hydrogen Containing fuels

DEFF Research Database (Denmark)

Jensen, Torben Kvist; Schramm, Jesper

2003-01-01

In-cylinder post flame oxidation of unburned hydro-carbons from crevices in a lean burn spark ignition engine has been examined for natural gas and mixtures of natural gas and a hydrogen containing producer gas. For this purpose a model was developed to describe the mixing of cold unburned...... reactants from crevices and hot burned bulk gas and to describe the oxidation of the unburned fuel. The post oxidation was described by a single step chemical reaction mechanism instead of detailed chemical kinetics in order to reduce the calculation time. However, the exploited Arrhenius expressions used...... to describe the chemical reactions were deduced from a detailed reaction mechanism. Different detailed reaction mechanisms were compared with results from combustion reactor experiments. Experiments and simulations were compared at different pressures and excesses of air similar to the conditions present...

Performance and Exhaust Emissions in a Natural-Gas Fueled Dual-Fuel Engine

Science.gov (United States)

Shioji, Masahiro; Ishiyama, Takuji; Ikegami, Makoto; Mitani, Shinichi; Shibata, Hiroaki

In order to establish the optimum fueling in a natural gas fueled dual fuel engine, experiments were done for some operational parameters on the engine performances and the exhaust emissions. The results show that the pilot fuel quantity should be increased and its injection timing should be advanced to suppress unburned hydrocarbon emission in the middle and low output range, while the quantity should be reduced and the timing retarded to avoid onset of knock at high loads. Unburned hydrocarbon emission and thermal efficiency are improved by avoiding too lean natural gas mixture by restricting intake charge air. However, the improvement is limited because the ignition of pilot fuel deteriorates with excessive throttling. It is concluded that an adequate combination of throttle control and equivalence ratio ensures low hydrocarbon emission and the thermal efficiency comparable to diesel operation.

Environmental optimisation of natural gas fired engines. Main report

Energy Technology Data Exchange (ETDEWEB)

Kvist, T. et al.

2010-10-15

The overall aim of the project has been to assess to which extent it is possible to reduce the emissions by adjusting the different engines examined and to determine the cost of the damage caused by emissions from natural gas combustion. However, only health and climate effects are included. The emissions of NO{sub x}, CO and UHC as well as the composition of the hydrocarbon emissions were measured for four different stationary lean-burn natural-gas fired engines installed at different combined heat and power (CHP) units in Denmark. The units were chosen to be representative of the natural gas fired engine-based power production in Denmark. The measurements showed that NO{sub x} emissions were relatively more sensitive to engine setting than UHC, CO and formaldehyde emissions. By reducing the NO{sub x} emissions to 40 % of the initial value (from 500 to 200 mg/m3(n) at 5 % O{sub 2}) the UHC emission was increased by 10 % to 50 % of the initial value. The electrical efficiency was reduced by 0.5 to 1.0 percentage point. Externalities in relation to power production are defined as the costs, which are not directly included in the price of the produced power. Health effects related to air pollution from power plants fall under this definition and usually dominate the results on external costs. For determination of these effects the exposure of the population, the impact of the exposure and the societal costs accompanying the impacts have been evaluated. As expected, it was found that when the engines are adjusted in order to reduce NO{sub x} emissions, the emission of UHC increases and vice versa. It was found that at high NO{sub x} emission levels (500 mg/m3{sub n} at 5 % O{sub 2}) the external costs related to the NO{sub x} emissions are 15 to 25 times the costs related to UHC emissions. At low NO{sub x} emission levels (200 mg/m3{sub n} at 5 % O{sub 2}) the costs related to NO{sub x} are 5 to 8 times the costs related to UHC emissions. Apparently, the harmfulness

Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel

Science.gov (United States)

Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

2012-11-20

A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

Variable composition hydrogen/natural gas mixtures for increased engine efficiency and decreased emissions

Energy Technology Data Exchange (ETDEWEB)

Sierens, R.; Rosseel, E.

2000-01-01

It is well known that adding hydrogen to natural gas extends the lean limit of combustion and that in this way extremely low emission levels can be obtained: even the equivalent zero emission vehicle (EZEV) requirements can be reached. The emissions reduction is especially important at light engine loads. In this paper results are presented for a GM V8 engine. Natural gas, pure hydrogen and different blends of these two fuels have been tested. The fuel supply system used provides natural gas/hydrogen mixtures in variable proportion, regulated independently of the engine operating condition. The influence of the fuel composition on the engine operating characteristics and exhaust emissions has been examined, mainly but not exclusively for 10 and 20% hydrogen addition. At least 10% hydrogen addition is necessary for a significant improvement in efficiency. Due to the conflicting requirements for low hydrocarbons and low NO{sub x} determining the optimum hythane composition is not straight-forward. For hythane mixtures with a high hydrogen fraction, it is found that a hydrogen content of 80% or less guarantees safe engine operation (no backfire nor knock), whatever the air excess factor. It is shown that to obtain maximum engine efficiency for the whole load range while taking low exhaust emissions into account, the mixture composition should be varied with respect to engine load.

Potential local use of natural gas or LNG from Hammerfest LNG plant

International Nuclear Information System (INIS)

Neeraas, Bengt Olav

1999-01-01

A base-load LNG plant is planned to be built in Norway, near by the northern most city in the world, Hammerfest. Natural gas from the Snoehvit-field will be transported by pipeline to Melkoeya, a few kilometres from Hammerfest, where the liquefaction plant is planned to be located. SINTEF Energy Research has performed a study in co-operation with the local authorities on potentials for the use of LNG and natural gas locally in the Hammerfest region. Combined power and heat production by lean-burn gas engine, low temperature freezing of high quality products by use of LNG cold and drying of fish products are some of the identified fields for the use of natural gas and LNG. The establishment of an industrial area, with fish processing industry and a central freezing storage near by Hammerfest has been suggested. The gas may be transported locally either as LNG, by tank lorry or container, or as gas in a small pipeline, depending on distance, amount and the actual use. (author)

NO adsorption behaviors of the MnOx catalysts in lean-burn atmospheres

International Nuclear Information System (INIS)

Guo, Li; Xian, Hui; Li, Qi-Feng; Chen, Da; Tan, Yi-Sheng; Zhang, Jing; Zheng, Li-Rong; Li, Xin-Gang

2013-01-01

Highlights: • α-Mn 2 O 3 is a promising NO x adsorber for lean-burn exhausts even at low temperatures. • NO x was weakly bonded on α-Mn 2 O 3 , but strongly bonded on β-MnO 2 . • NO could efficiently adsorb/desorb within the lean/rich cyclings over α-Mn 2 O 3 . • The superficial oxygen species plays a key role for the NO oxidation over α-Mn 2 O 3 . • The NO adsorption and oxidation follow the L–H and/or E–R mechanism over α-Mn 2 O 3 . -- Abstract: NO x emission control of lean-burn engines is one of the great challenges in the world. Herein, the MnO x model catalysts with the different calcination temperatures were synthesized to investigate their NO adsorbability for lean-burn exhausts. The transformation from (β-)MnO 2 to (α-)Mn 2 O 3 following the increased calcination temperatures was evidenced from the viewpoint of the local atomic level. Among these samples, the one calcined at 550 °C containing the single α-Mn 2 O 3 phase displayed the best NO adsorbability: NO was mainly adsorbed in the forms of NO/nitrites and NO 2 /nitrates at the low and high temperatures, respectively; the NO oxidation ability displayed the volcano-shape following the increased operating temperatures, and reached the maximum, i.e. 92.4% of the NO-to-NO 2 conversion, at 250 °C. Moreover, this sample presented the efficiently reversible NO adsorption/desorption performance in alternative lean-burn/fuel-rich atmospheres, due to the weakly bonded NO x on it. The superficial oxygen species plays a critical role for the NO oxidation over α-Mn 2 O 3 . The consumed superficial oxygen could be further compensated by the gaseous and lattice oxygen therein. Our findings show that the α-Mn 2 O 3 material is a promising NO x adsorber for lean-burn exhausts even at low operating temperatures

Natural gas in the transportation sector

Energy Technology Data Exchange (ETDEWEB)

Ask, T Oe; Einang, P M; Stenersen, D [MARINTEK (Norway)

1996-12-01

The transportation sector is responsible for more than 50% of all oil products consumed, and it is the fastest growing oil demand sector and the fastest growing source of emissions. During the last 10 years there have been a considerable and growing effort in developing internal combustion gas engines. This effort has resulted in gas engines with efficiencies comparable to the diesel engines and with emissions considerably lower than engines burning conventional fuels. This development offers us opportunities to use natural gas very efficiently also in the transportation sector, resulting in reduced emissions. However, to utilize all the built in abilities natural gas has as engine fuel, the natural gas composition must be kept within relatively narrow limits. This is the case with both diesel and gasoline today. A further development require therefore specified natural gas compositions, and the direct use of pipeline natural gas as today would only in limited areas be acceptable. An interesting possibility for producing a specified natural gas composition is by LNG (Liquid Natural Gas) production. (EG)

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

Science.gov (United States)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

Improvement performance and emissions in a diesel engine dual-fueled with natural gas; Tennen gas dual fuel diesel kikan no seino haishutsu gas tokusei no kaizen

Energy Technology Data Exchange (ETDEWEB)

Nakayama, S; Okamoto, T; Kusaka, J; Daisho, Y; Kihara, R; Saito, T [Waseda University, Tokyo (Japan)

1997-10-01

This paper deals with a study on combustion and emission characteristics of a direct injection diesel engine dual-fueled with natural gas. Dual fueling systems tend to emit high unburned fuel especially at low load, resulting in a decreased thermal efficiency. This is because natural gas-air mixtures are too lean for flame to propagate under low load conditions. Intake charge heating and uncooled EGR are very useful to improve emissions and thermal efficiency at low load. Such favorable effects are supported by NO kinetic simulations. 2 refs., 13 figs.

Cyclic variations of fuel-droplet distribution during the early intake stroke of a lean-burn stratified-charge spark-ignition engine

Energy Technology Data Exchange (ETDEWEB)

Aleiferis, P.G. [Imperial College London, Department of Mechanical Engineering, London (United Kingdom); University College London, Department of Mechanical Engineering, London (United Kingdom); Hardalupas, Y.; Taylor, A.M.K.P. [Imperial College London, Department of Mechanical Engineering, London (United Kingdom); Ishii, K. [Honda International Technical School, Saitama (Japan); Urata, Y. [Tochigi R and D Centre, Honda R and D Co., Ltd, Tochigi (Japan)

2005-11-01

Lean-burn spark-ignition engines exhibit higher efficiency and lower specific emissions in comparison with stoichiometrically charged engines. However, as the air-to-fuel (A/F) ratio of the mixture is made leaner than stoichiometric, cycle-by-cycle variations in the early stages of in-cylinder combustion, and subsequent indicated mean effective pressure (IMEP), become more pronounced and limit the range of lean-burn operation. Viable lean-burn engines promote charge stratification, the mixture near the spark plug being richer than the cylinder volume averaged value. Recent work has shown that cycle-by-cycle variations in the early stages of combustion in a stratified-charge engine can be associated with variations in both the local value of A/F ratio near the spark plug around ignition timing, as well as in the volume averaged value of the A/F ratio. The objective of the current work was to identify possible sources of such variability in A/F ratio by studying the in-cylinder field of fuel-droplet distribution during the early intake stroke. This field was visualised in an optical single-cylinder 4-valve pentroof-type spark-ignition engine by means of laser-sheet illumination in planes parallel to the cylinder head gasket 6 and 10 mm below the spark plug. The engine was run with port-injected isooctane at 1500 rpm with 30% volumetric efficiency and air-to-fuel ratio corresponding to both stoichiometric firing (A/F=15, {phi} =1.0) and mixture strength close to the lean limit of stable operation (A/F=22, {phi} =0.68). Images of Mie intensity scattered by the cloud of fuel droplets were acquired on a cycle-by-cycle basis. These were studied in order to establish possible correlations between the cyclic variations in size, location and scattered-light intensity of the cloud of droplets with the respective variations in IMEP. Because of the low level of Mie intensity scattered by the droplets and because of problems related to elastic scattering on the walls of the

Emissions and efficiency of a domestic gas stove burning natural gases with various compositions

International Nuclear Information System (INIS)

Yungchang Ko; Tahui Lin

2003-01-01

The heating value of a fuel, which depends on its composition, strongly affects burner performance. Using the same gas stove to burn natural gas with various heating values is inappropriate and hazardous due to the possible occurrence of incomplete combustion (i.e. a great increase of CO emissions and/or soot formation), liftoff, flashback and inadequate heat input. In this study, we aim to assess the effects of changes in gas composition on burner performance and propose suitable design or operational factors of domestic gas stoves burning natural gas with various heating values. A single gas burner, originally designed for burning natural gas with low heating value, is adopted to investigate the effects of variations in gas composition on the burner performance. The influence of five significant parameters, including gas composition, primary aeration, gas flow rate (heat input), gas supply pressure, and loading height, on the thermal efficiency and CO emissions were reported and discussed. Using natural gas with high heating value instead of natural gas with low heating value results in a decrease in thermal efficiency (due to higher thermal input) and an increase in CO emission (caused by incomplete combustion). These problems can be significantly improved by decreasing the gas pressure to a suitable value, by enlarging the primary aeration to a favorable level, by selecting a proper thermal input, or by adjusting the optimized heating height. (Author)

Internal Combustion Engine Powered by Synthesis Gas from Pyrolysed Plastics

Directory of Open Access Journals (Sweden)

Chríbik Andrej

2016-07-01

Full Text Available The article discusses the application of synthesis gas from pyrolysis of plastics in petrol engine. The appropriate experimental measurements were performed on a combustion engine LGW 702 designated for micro-cogeneration unit. The power parameters, economic parameters in term of brake specific fuel consumption, and internal parameters of the engine were compared to the engine running on the reference fuel - natural gas and synthesis gas. Burning synthesis gas leads to decreased performance by about 5% and to increased mass hourly consumption by 120 %. In terms of burning, synthesis gas has similar properties as natural gas. Compared with [5] a more detailed study has been prepared on the effects of angle of spark advance on the engine torque, giving more detailed assessment of engine cycle variability and considering specification of start and end of combustion in the logarithm p-V diagram.

Burned gas and unburned mixture composition prediction in biodiesel-fuelled compression igniton engine

International Nuclear Information System (INIS)

Chuepeng, S.; Komintarachati, C.

2009-01-01

A prediction of burned gas and unburned mixture composition from a variety of methyl ester based bio diesel combustion in compression ignition engine, in comparison with conventional diesel fuel is presented. A free-energy minimisation scheme was used to determine mixture composition. Firstly, effects of bio diesel type were studied without exhaust gas recirculation (EGR). The combustion of the higher hydrogen-to-carbon molar ratio (H/C) bio diesel resulted in lower carbon dioxide and oxygen emissions but higher water vapour in the exhaust gases, compared to those of lower H/C ratios. At the same results also show that relative air-to-fuel ratio, that bio diesel combustion gases contain a higher amount of water vapour and a higher level of carbon dioxide compared to those of diesel. Secondly, influences of EGR (burned gas fraction) addition to bio diesel-fuelled engine on unburned mixture were simulated. For both diesel and bio diesel, the increased burned gas fraction addition to the fresh charge increased carbon dioxide and water vapour emissions while lowering oxygen content, especially for the bio diesel case. The prediction was compared with experimental results from literatures; good agreement was found. This can be considered to be a means for explaining some phenomenon occurring in bio diesel-fuelled engines. (author)

Survey of modern power plants driven by diesel and gas engines

Energy Technology Data Exchange (ETDEWEB)

Niemi, S. [Turku Polytechnic, Turku (Finland)

1997-12-31

This report surveys the latest technology of power plants driven by reciprocating internal combustion (IC) engines, from information collected from publications made mainly during the 1990`s. Diesel and gas engines are considered competitive prime movers in power production due mainly to their high full- and part-load brake thermal efficiency, ability to burn different fuels, short construction time and fast start-ups. The market for engine power plants has grown rapidly, with estimated total orders for reciprocating engines of 1 MW output and more reaching the 5000 unit level, (10 GW), between June 1995 and May 1996. Industrialized countries much prefer combined heat and power (CHP) production. Intense interest has been shown in recent years in alternative gas fuels; natural gas appears to be the most promising, but liquid petroleum gas, gas from sewage disposal plants, landfill gas and other biogases, as well as wood gas have also been recognized as other alternatives. Liquid alternatives such as fuels and pyrolysis oil have also been mentioned, in addition to information on coal burning engines. The percentage of gas engines used has increased and different ones are being developed, based on either the traditional spark ignition (SI), dual-fuel technology or the more recent high pressure gas injection system. In cold climates, energy production is largely based on CHP plants. Waste heat is utilized for local, regional or district heating or for industrial uses like drying, heating, cooling etc. Even radiative and convective heat from gen-set surfaces are employed, and boilers are used with exhaust outlet temperatures of below dew point. Combined cycle schemes, including turbo compound systems and steam turbines, are also incorporated into engine power plants in order to increase output and efficiency. Two-stroke, low-speed diesel engine plants show the highest electric efficiencies, with combined cycle plants reaching up to 54 %, while gas engine plants achieved

Survey of modern power plants driven by diesel and gas engines

Energy Technology Data Exchange (ETDEWEB)

Niemi, S [Turku Polytechnic, Turku (Finland)

1998-12-31

This report surveys the latest technology of power plants driven by reciprocating internal combustion (IC) engines, from information collected from publications made mainly during the 1990`s. Diesel and gas engines are considered competitive prime movers in power production due mainly to their high full- and part-load brake thermal efficiency, ability to burn different fuels, short construction time and fast start-ups. The market for engine power plants has grown rapidly, with estimated total orders for reciprocating engines of 1 MW output and more reaching the 5000 unit level, (10 GW), between June 1995 and May 1996. Industrialized countries much prefer combined heat and power (CHP) production. Intense interest has been shown in recent years in alternative gas fuels; natural gas appears to be the most promising, but liquid petroleum gas, gas from sewage disposal plants, landfill gas and other biogases, as well as wood gas have also been recognized as other alternatives. Liquid alternatives such as fuels and pyrolysis oil have also been mentioned, in addition to information on coal burning engines. The percentage of gas engines used has increased and different ones are being developed, based on either the traditional spark ignition (SI), dual-fuel technology or the more recent high pressure gas injection system. In cold climates, energy production is largely based on CHP plants. Waste heat is utilized for local, regional or district heating or for industrial uses like drying, heating, cooling etc. Even radiative and convective heat from gen-set surfaces are employed, and boilers are used with exhaust outlet temperatures of below dew point. Combined cycle schemes, including turbo compound systems and steam turbines, are also incorporated into engine power plants in order to increase output and efficiency. Two-stroke, low-speed diesel engine plants show the highest electric efficiencies, with combined cycle plants reaching up to 54 %, while gas engine plants achieved

Rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation

Science.gov (United States)

Milcarek, Ryan J.; Ahn, Jeongmin

2018-03-01

Micro-tubular flame-assisted fuel cells (mT-FFC) were recently proposed as a modified version of the direct flame fuel cell (DFFC) operating in a dual chamber configuration. In this work, a rich-burn, quick-mix, lean-burn (RQL) combustor is combined with a micro-tubular solid oxide fuel cell (mT-SOFC) stack to create a rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation system. The system is tested for rapid startup and achieves peak power densities after only 35 min of testing. The mT-FFC power density and voltage are affected by changes in the fuel-lean and fuel-rich combustion equivalence ratio. Optimal mT-FFC performance favors high fuel-rich equivalence ratios and a fuel-lean combustion equivalence ratio around 0.80. The electrical efficiency increases by 150% by using an intermediate temperature cathode material and improving the insulation. The RFQL combustor and power generation system achieves rapid startup, a simplified balance of plant and may have applications for reduced NOx formation and combined heat and power.

Electric Engines to Gas

International Nuclear Information System (INIS)

Novoa, M.G.

1996-01-01

Environmental pollution and specially air pollution, it is produced in a wide range by exhaust gases of internal combustion engines, those which are used to generate energy. Direct use of fossil combustibles as petroleum derivatives and coal produces large quantities of harmful elements to ecology equilibrium. Whit the objective of reducing this pollutant load has been development thermoelectric plants whit turbine to gas or to steam, those which are moved by internal combustion engines. Gas engines can burn most of available gases, as both solid waste and wastewater treatment plants biogas, propane gas, oil-liquefied gas or natural gas. These gases are an alternative and clean energy source, and its efficiency in internal combustion engines is highest compared whit other combustibles as gasoline-motor or diesel

Measurement of laminar burning velocities and Markstein lengths of diluted hydrogen-enriched natural gas

Energy Technology Data Exchange (ETDEWEB)

Miao, Haiyan; Jiao, Qi; Huang, Zuohua; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China)

2009-01-15

The laminar flame characteristics of natural gas-hydrogen-air-diluent gas (nitrogen/CO{sub 2}) mixtures were studied in a constant volume combustion bomb at various diluent ratios, hydrogen fractions and equivalence ratios. Both unstretched laminar burning velocity and Markstein length were obtained. The results showed that hydrogen fraction, diluent ratio and equivalence ratio have combined influence on laminar burning velocity and flame instability. The unstretched laminar burning velocity is reduced at a rate that is increased with the increase of the diluent ratio. The reduction effect of CO{sub 2} diluent gas is stronger than that of nitrogen diluent gas. Hydrogen-enriched natural gas with high hydrogen fraction can tolerate more diluent gas than that with low hydrogen fraction. Markstein length can either increase or decrease with the increase of the diluent ratio, depending on the hydrogen fraction of the fuel. (author)

Extending Lean and Exhaust Gas Recirculation-Dilute Operating Limits of a Modern Gasoline Direct-Injection Engine Using a Low-Energy Transient Plasma Ignition System

Energy Technology Data Exchange (ETDEWEB)

Sevik, James; Wallner, Thomas; Pamminger, Michael; Scarcelli, Riccardo; Singleton, Dan; Sanders, Jason

2016-05-24

The efficiency improvement and emissions reduction potential of lean and exhaust gas recirculation (EGR)-dilute operation of spark-ignition gasoline engines is well understood and documented. However, dilute operation is generally limited by deteriorating combustion stability with increasing inert gas levels. The combustion stability decreases due to reduced mixture flame speeds resulting in significantly increased combustion initiation periods and burn durations. A study was designed and executed to evaluate the potential to extend lean and EGR-dilute limits using a low-energy transient plasma ignition system. The low-energy transient plasma was generated by nanosecond pulses and its performance compared to a conventional transistorized coil ignition (TCI) system operated on an automotive, gasoline direct-injection (GDI) single-cylinder research engine. The experimental assessment was focused on steady-state experiments at the part load condition of 1500 rpm 5.6 bar indicated mean effective pressure (IMEP), where dilution tolerance is particularly critical to improving efficiency and emission performance. Experimental results suggest that the energy delivery process of the low-energy transient plasma ignition system significantly improves part load dilution tolerance by reducing the early flame development period. Statistical analysis of relevant combustion metrics was performed in order to further investigate the effects of the advanced ignition system on combustion stability. Results confirm that at select operating conditions EGR tolerance and lean limit could be improved by as much as 20% (from 22.7 to 27.1% EGR) and nearly 10% (from λ = 1.55 to 1.7) with the low-energy transient plasma ignition system.

Development of fast-burn combustion with elevated coolant temperatures for natural gas engines. Final report, May 1985-May 1990

Energy Technology Data Exchange (ETDEWEB)

Bruch, K.L.; Dennis, J.W.

1990-09-01

The overall objective of the work was to improve the state of the art in the gas fired spark ignited engine for use in a cogeneration system. Four characteristics were enhanced for cogeneration, namely, Low Pressure Gas Induction, Improved Shaft Thermal Efficiency, Low NOx Emissions, and Increased Jacket Coolant Temperature. Using Taguchi methods and statistical design of experiment methodologies, an engine design evolved that exhibited: The ability to run satisfactorily on supply gas pressure as low as 1.5 psig (goal: 1 psig); A brake specific fuel consumption as low as 6950 Btu/hp-hr (36.6% thermal efficiency) at 2 gm/hp-hr NOx (goal: 7000 acceptable, 6800 excellent with NOx no more than 2 gm/hp-hr); A jacket water coolant system (with oil cooler on the same circuit) temperature of 225 F (goal); and The ability to burn gas with Methane Number as low as 67 (goal).

Investigation of combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine system

International Nuclear Information System (INIS)

Yin Juan; Weng Yiwu

2011-01-01

The goals of this research were to investigate the combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine. The characteristics of lean burn catalytic combustion were investigated by utilising 1D heterogeneous plug flow model which was validated by experiments. The effects of operating parameters on catalytic combustion were numerically analysed. The system models were built in ASPEN Plus and three independent design variables, i.e. compressor pressure ratio (PR), regenerator effectiveness (RE) and turbine inlet temperature (TIT) were selected to analyse the thermodynamic performance of the thermal cycle. The main results show that: simulations from 1D heterogeneous plug flow model can capture the trend of catalytic combustion and describe the behavior of the catalytic monolith in detail. Inlet temperature is the most significant parameter that impacts operation of the catalytic combustor. When TIT and RE are constant, the increase of PR results in lowering the inlet temperature of the catalytic combustor, which results in decreasing methane conversion. The peak thermal efficiency and the optimal PR at a constant TIT increase with the increase of TIT; and at the constant PR, the thermal efficiency increases with the increase of TIT. However, with lower TIT conditions, the optimal PR and the peak efficiency at a constant TIT of the LBCCGT cycle are relative low to that of the conventional cycle. When TIT and PR are constant, the decrease of RE may result in lower methane conversion. The influences of RE on the methane conversion and the thermal efficiency are more significant at higher PRs. The higher thermal efficiency for the lower RE is achieved at lower PR.

Performance and exhaust emissions in a natural-gas fueled dual-fuel engine; Tennen gas dual fuel kikan no seino oyobi haiki tokusei

Energy Technology Data Exchange (ETDEWEB)

Shioji, M.; Ishiyama, T.; Shibata, H. [Kyoto Univ., Kyoto (Japan). Inst. of Atomic Energy; Ikegami, M. [Fukui Institute of Technology, Fukui (Japan). Faculty of Engineering

2000-07-25

In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. The increase in pilot gas oil amount is effective for low-load operation and the adequate combination of throttle control and equivalence ratio ensures low hydrocarbon emission and the thermal efficiency comparable to diesel operation. (author)

Model reduction of a lean NOx trap catalyst model

NARCIS (Netherlands)

Nauta, K.M.

2008-01-01

The desire to increase fuel efficiency and reduce carbon dioxide emissions of vehicles has led to an increased use of vehicles equipped with lean-burn engines, such as diesel and lean-burn gasoline engines. This type of engine uses excess oxygen when compared to the amount required to

Economic feasibility of hydrogen enrichment for reducing NOx emissions from landfill gas power generation alternatives: A comparison of the levelized cost of electricity with present strategies

International Nuclear Information System (INIS)

Kornbluth, Kurt; Greenwood, Jason; Jordan, Eddie; McCaffrey, Zach; Erickson, Paul A.

2012-01-01

Based on recent research showing that hydrogen enrichment can lower NO x emissions from landfill gas combustion below future NO x emission control standards imposed by both federal and California state regulations, an investigation was performed to compare the levelized cost of electricity of this technology with other options. In this cost study, a lean-burn reciprocating engine with no after-treatment was the baseline case to compare six other landfill gas-to-energy projects. These cases include a lean burn engine with selective catalytic reduction after treatment, a lean-burn microturbine, and four variations on an ultra-lean-burn engine utilizing hydrogen enrichment with each case using a different method of hydrogen production. Only hydrogen enrichment with an in-stream autothermal fuel reformer was shown to be potentially cost-competitive with current strategies for reaching the NO x reduction target in IC engines. - Highlights: ► Levelized cost of electricity for hydrogen enriched combustion was compared. ► Various ultra-lean-burn engines and microturbines with hydrogen were analyzed. ► Combustion with an autothermal fuel reformer was potentially cost-competitive.

A study on the amount of pilot injection and its effects on rich and lean boundaries of the premixed CNG/air mixture for a CNG/diesel dual-fuel engine

Energy Technology Data Exchange (ETDEWEB)

Zhiqiang Lin; Wanhua Su [Tianjin University (China). State Key Laboratory of Engines

2003-07-01

A sequential port injection, lean-burn, fully electronically-controlled compressed natural gas (CNG)/diesel dual-fuel engine has been developed based on a turbo-charged and inter-cooled direct injection (D.I.) diesel engine. During the optimisation of engine overall performance, the effects of pilot diesel and premixed CNG/air mixture equivalence ratio on emissions (CO, HC, NO{sub x}, soot), knocking, misfire and fuel economy are studied. The rich and lean boundaries of the premixed CNG/air mixture versus engine load are also provided, considering the acceptable values of NO{sub x} and THC emissions, respectively. It is interesting to find that there is a critical amount of pilot diesel for each load and speed point, which proved to be the optimum amount of pilot fuel. Any decrease in the amount of pilot diesel from this optimum amount results in an increase of NO{sub x} emissions, because the premixed CNG/air mixture must be made richer, otherwise THC emissions would increase. However, the soot emissions remain almost unchanged at a very low level. (author)

NO adsorption behaviors of the MnO{sub x} catalysts in lean-burn atmospheres

Energy Technology Data Exchange (ETDEWEB)

Guo, Li [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Applied Catalysis Science and Technology, Tianjin 300072 (China); The Co-innovation Center of Chemistry and Chemical Engineering of Tianjin, Tianjin 300072 (China); Xian, Hui [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Pei-Yang Distillation Engineering Limited Company, Tianjin 300072 (China); Li, Qi-Feng; Chen, Da [Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072 (China); Tan, Yi-Sheng [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001 (China); Zhang, Jing; Zheng, Li-Rong [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li, Xin-Gang, E-mail: xingang_li@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Applied Catalysis Science and Technology, Tianjin 300072 (China); The Co-innovation Center of Chemistry and Chemical Engineering of Tianjin, Tianjin 300072 (China)

2013-09-15

Highlights: • α-Mn{sub 2}O{sub 3} is a promising NO{sub x} adsorber for lean-burn exhausts even at low temperatures. • NO{sub x} was weakly bonded on α-Mn{sub 2}O{sub 3}, but strongly bonded on β-MnO{sub 2}. • NO could efficiently adsorb/desorb within the lean/rich cyclings over α-Mn{sub 2}O{sub 3}. • The superficial oxygen species plays a key role for the NO oxidation over α-Mn{sub 2}O{sub 3}. • The NO adsorption and oxidation follow the L–H and/or E–R mechanism over α-Mn{sub 2}O{sub 3}. -- Abstract: NO{sub x} emission control of lean-burn engines is one of the great challenges in the world. Herein, the MnO{sub x} model catalysts with the different calcination temperatures were synthesized to investigate their NO adsorbability for lean-burn exhausts. The transformation from (β-)MnO{sub 2} to (α-)Mn{sub 2}O{sub 3} following the increased calcination temperatures was evidenced from the viewpoint of the local atomic level. Among these samples, the one calcined at 550 °C containing the single α-Mn{sub 2}O{sub 3} phase displayed the best NO adsorbability: NO was mainly adsorbed in the forms of NO/nitrites and NO{sub 2}/nitrates at the low and high temperatures, respectively; the NO oxidation ability displayed the volcano-shape following the increased operating temperatures, and reached the maximum, i.e. 92.4% of the NO-to-NO{sub 2} conversion, at 250 °C. Moreover, this sample presented the efficiently reversible NO adsorption/desorption performance in alternative lean-burn/fuel-rich atmospheres, due to the weakly bonded NO{sub x} on it. The superficial oxygen species plays a critical role for the NO oxidation over α-Mn{sub 2}O{sub 3}. The consumed superficial oxygen could be further compensated by the gaseous and lattice oxygen therein. Our findings show that the α-Mn{sub 2}O{sub 3} material is a promising NO{sub x} adsorber for lean-burn exhausts even at low operating temperatures.

Environmental and energy efficiency evaluation of residential gas and heat pump heating

International Nuclear Information System (INIS)

Ganji, A.R.

1993-01-01

Energy efficiency and source air pollutant emission factors of gas heaters, gas engine heat pumps, and electric heat pumps for domestic heating have been evaluated and compared. The analysis shows that with the present state of technology, gas engine heat pumps have the highest energy efficiency followed by electric heat pumps and then gas heaters. Electric heat pumps produce more than twice as much NO x , and comparable CO 2 and CO per unit of useful heating energy compared to natural gas heaters. CO production per unit of useful heating energy from gas engine heat pumps without any emission control is substantially higher than electric heat pumps and natural gas heaters. NO x production per unit of useful heating energy from natural gas engine heat pumps (using lean burn technology) without any emission control is about the same as effective NO x production from electric heat pumps. Gas engine heat pumps produce about one-half CO 2 compared to electric heat pumps

Challenges and solutions in natural gas engine development and productions

Energy Technology Data Exchange (ETDEWEB)

Ahmadi, Mahdi; Izanloo, Hossein [Irankhodro Powertrain Co. (IPCO) (Iran)

2008-07-01

As an alternative fuel, natural gas is generally accepted for internal combustion engines and some developments have been conducted in order to adopt it for the road vehicles and stationary applications. Foresights shows natural gas vehicles will be a part of the future transportation technology regarding to their mid and long-term benefits. Therefore inherent problems of natural gas engine technology should be overcome to produce a competitive engine. In this paper major problems and their possible solutions in developing and producing natural gas engine for passenger cars are detailed and discussed. Challenging materials are sorted and presented in two categorizes: technical and econo-strategical problems. In the technical section major difficulties faced in components or systems of natural gas engine are analysed in different aspects of design, validation, and production. In addition problems arisen from the fuel characteristics which influence the function and durability of engine are argued. Subjects like freezing in gas regulator, cold start fuel injection, gas leakage, impurities within compressed natural gas, variation in fuel composition, thermo-mechanics of cylinder head and block, wear of valve seat inserts, spark plug erosion, back-fire phenomenon, engine oil quality requirement, low power density and mileage are described. In the econo-strategical discussion, challenges like limited gas distribution infrastructure, lack of specific manufacturing standards and codes, and non-dedicated emission standards are explained. In both part of the paper a comprehensive view is extended to clarify the effect, risk and solutions of each problem. Due to the fact that almost all information and analysis presented in this paper are based on the experience of developing a natural gas engine family, and an extensive literature review, discussions and conclusions could be useful as a guide line for future natural gas engine projects. (orig.)

Effects of natural gas composition on performance and regulated, greenhouse gas and particulate emissions in spark-ignition engines

International Nuclear Information System (INIS)

Amirante, R.; Distaso, E.; Di Iorio, S.; Sementa, P.; Tamburrano, P.; Vaglieco, B.M.; Reitz, R.D.

2017-01-01

Highlights: • The influence of natural gas composition is investigated. • Real-time methane/propane fuel mixtures were realized. • IMEP, HRR and MBF were used to evaluate the effects on engine performance. • Gaseous, greenhouse and Particulate emissions were studied. • The propane content strongly influenced performance and emissions. - Abstract: In vehicles fueled with compressed natural gas, a variation in the fuel composition can have non-negligible effects on their performance, as well as on their emissions. The present work aimed to provide more insight on this crucial aspect by performing experiments on a single-cylinder port-fuel injected spark-ignition engine. In particular, methane/propane mixtures were realized to isolate the effects of a variation of the main constituents in natural gas on engine performance and associated pollutant emissions. The propane volume fraction was varied from 10 to 40%. Using an experimental procedure designed and validated to obtain precise real-time mixture fractions to inject directly into the intake manifold. Indicative Mean Effective Pressure, Heat Release Rate and Mass Burned Fraction were used to evaluate the effects on engine performance. Gaseous emissions were measured as well. Particulate Mass, Number and Size Distributions were analyzed with the aim to identify possible correlations existing between fuel composition and soot emissions. Emissions samples were taken from the exhaust flow, just downstream of the valves. Opacity was measured downstream the Three-Way Catalyst. Three different engine speeds were investigated, namely 2000, 3000 and 4000 rpm. Stoichiometric and full load conditions were considered in all tests. The results were compared with pure methane and propane, as well as with natural gas. The results indicated that both performance and emissions were strongly influenced by the variation of the propane content. Increasing the propane fraction favored more complete combustion and increased NO

Prediction of knock limited operating conditions of a natural gas engine

International Nuclear Information System (INIS)

Soylu, Seref

2005-01-01

Computer models of engine processes are valuable tools for predicting and analyzing engine performance and allow exploration of many engine design alternatives in an inexpensive fashion. In the present work, a zero-dimensional, two zone thermodynamic model was used to determine the knock limited operating conditions of a natural gas engine. Experimentally based burning rate models were used for flame initiation and propagation calculations. A knock model was incorporated with the zero-dimensional model. Comparison of the measured and calculated cylinder pressure data indicated that the model is able to match the measured cylinder pressure data with less than 8% error in magnitudes if the computations are started at the experimental spark timing. The knock predictions agreed with the measurements also. With the established knock model, it is possible not only to investigate whether knock is observed with changing operating and design parameters, but also to evaluate their effects on the maximum possible knock intensity

Wartsila 32DF, the dual-fuel engine

Energy Technology Data Exchange (ETDEWEB)

Anon.

1999-06-01

This paper gives details of the development of the Wartsila 32DF duel-fuel lean-burn engine that can burn liquid or gaseous fuels, and reports on the installation of four of the engines in Turkey. The combustion process, and the design of the gas admission, pilot fuel, cylinder control, air-fuel control, and engine control and monitoring systems are described. The advantages of the engine are discussed.

Analysis of Adsorbed Natural Gas Tank Technology

Science.gov (United States)

Knight, Ernest; Schultz, Conrad; Rash, Tyler; Dohnke, Elmar; Stalla, David; Gillespie, Andrew; Sweany, Mark; Seydel, Florian; Pfeifer, Peter

With gasoline being an ever decreasing finite resource and with the desire to reduce humanity's carbon footprint, there has been an increasing focus on innovation of alternative fuel sources. Natural gas burns cleaner, is more abundant, and conforms to modern engines. However, storing compressed natural gas (CNG) requires large, heavy gas cylinders, which limits space and fuel efficiency. Adsorbed natural gas (ANG) technology allows for much greater fuel storage capacity and the ability to store the gas at a much lower pressure. Thus, ANG tanks are much more flexible in terms of their size, shape, and weight. Our ANG tank employs monolithic nanoporous activated carbon as its adsorbent material. Several different configurations of this Flat Panel Tank Assembly (FPTA) along with a Fuel Extraction System (FES) were examined to compare with the mass flow rate demands of an engine.

Influence of the altitude on the burning velocity of the natural gas

International Nuclear Information System (INIS)

Arrieta, Andres Amell; Garcia Posada, Jorge Mario; Quilindo Valencia, Arvey; Henao Vallejo, Diego Alberto

2004-01-01

By the increasing use of natural gas in cities of Latin America located to high altitude, is necessary to study the effect of the altitude on the combustion, for example the burning velocity. This work is an experimental study of as it changes to the burning velocity with the altitude, being made test in sites with altitude of 40, 550, 1.020, 1.550, 2.040 and 2.550 meters. The result was that the variations are slight

CO Emissions from Gas Engines Operating on Biomass Producer Gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Jensen, T. K.; Henriksen, Ulrik Birk

2004-01-01

High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...

Natural gas in a D. I. diesel engine. A comparison of two different ways. [Direct injection diesel enginer

Energy Technology Data Exchange (ETDEWEB)

Jun-ming, Qu; Sorenson, S.C.; Kofoed, E.

1987-01-01

A D.I. diesel engine was modified for natural gas operation with pilot injection and with spark ignition so that a comparative analysis of these two different ways of using natural gas could be made. The results of the experiments indicate that for a diesel engine, it is possible that the operating characteristics of a straight natural gas engine are comparable with those of a diesel/gas engine at the same compression ratio and speed. For a dual fuel engine with pilot injection the best diesel/gas ratio by energy content is approximately 20/80 at full load operation. For straight natural gas engine with spark ignition, quality governed natural gas operation has good efficiency but poor NOx emissions. This problem could be improved through throttle controlled operation. These two different ways of using natural gas are best suited to stationary engines.

Development of compressed natural gas/diesel dual-fuel turbocharged compressed ignition engine

Energy Technology Data Exchange (ETDEWEB)

Shenghua, L.; Ziyan, W.; Jiang, R. [Xi' an Jiaotong Univ. (China). Dept. of Automotive Engineering

2003-09-01

A natural gas and diesel dual-fuel turbocharged compression ignition (CI) engine is developed to reduce emissions of a heavy-duty diesel engine. The compressed natural gas (CNG) pressure regulator is specially designed to feed back the boost pressure to simplify the fuel metering system. The natural gas bypass improves the engine response to acceleration. The modes of diesel injection are set according to the engine operating conditions. The application of honeycomb mixers changes the flowrate shape of natural gas and reduces hydrocarbon (HC) emission under low-load and lowspeed conditions. The cylinder pressures of a CI engine fuelled with diesel and dual fuel are analysed. The introduction of natural gas makes the ignition delay change with engine load. Under the same operating conditions, the emissions of smoke and NO{sub x} from the dual-fuel engine are both reduced. The HC and CO emissions for the dual-fuel engine remain within the range of regulation. (Author)

Effect of advanced injection timing on emission characteristics of diesel engine running on natural gas

Energy Technology Data Exchange (ETDEWEB)

Nwafor, O.M.I. [Department of Mechanical Engineering, Federal University of Technology, Owerri, Imo State (Nigeria)

2007-11-15

There has been a growing concern on the emission of greenhouse gases into the atmosphere, whose consequence is global warming. The sources of greenhouse gases have been identified, of which the major contributor is the combustion of fossil fuel. Researchers have intensified efforts towards identifying greener alternative fuel substitutes for the present fossil fuel. Natural gas is now being investigated as potential alternative fuel for diesel engines. Natural gas appears more attractive due to its high octane number and perhaps, due to its environmental friendly nature. The test results showed that alternative fuels exhibit longer ignition delay, with slow burning rates. Longer delays will lead to unacceptable rates of pressure rise with the result of diesel knock. This work examines the effect of advanced injection timing on the emission characteristics of dual-fuel engine. The engine has standard injection timing of 30 BTDC. The injection was first advanced by 5.5 and given injection timing of 35.5 BTDC. The engine performance was erratic on this timing. The injection was then advanced by 3.5 . The engine performance was smooth on this timing especially at low loading conditions. The ignition delay was reduced through advanced injection timing but tended to incur a slight increase in fuel consumption. The CO and CO{sub 2} emissions were reduced through advanced injection timing. (author)

Effects of NOX Storage Component on Ammonia Formation in TWC for Passive SCR NOX Control in Lean Gasoline Engines

Energy Technology Data Exchange (ETDEWEB)

Prikhodko, Vitaly Y. [ORNL; Pihl, Josh A. [ORNL; Toops, Todd J. [ORNL; Parks, II, James E. [ORNL

2018-04-01

A prototype three-way catalyst (TWC) with NOX storage component was evaluated for ammonia (NH3) generation on a 2.0-liter BMW lean burn gasoline direct injection engine as a component in a passive ammonia selective catalytic reduction (SCR) system. The passive NH3 SCR system is a potential approach for controlling nitrogen oxides (NOX) emissions from lean burn gasoline engines. In this system, NH3 is generated over a close-coupled TWC during periodic slightly-rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst. Adding a NOX storage component to a TWC provides two benefits in the context of a passive SCR system: (1) enabling longer lean operation by storing NOX upstream and preserving NH3 inventory on the downstream SCR catalyst; and (2) increasing the quantity and rate of NH3 production during rich operation. Since the fuel penalty associated with passive SCR NOX control depends on the fraction of time that the engine is running rich rather than lean, both benefits (longer lean times and shorter rich times achieved via improved NH3 production) will decrease the passive SCR fuel penalty. However, these benefits are primarily realized at low to moderate temperatures (300-500 °C), where the NOX storage component is able to store NOX, with little to no benefit at higher temperatures (>500 °C), where NOX storage is no longer effective. This study discusses engine parameters and control strategies affecting the NH3 generation over a TWC with NOX storage component.

Internal combustion engine for natural gas compressor operation

Energy Technology Data Exchange (ETDEWEB)

Hagen, Christopher; Babbitt, Guy

2016-12-27

This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a method is featured which includes placing a first cylinder of an internal combustion engine in a compressor mode, and compressing a gas within the first cylinder, using the cylinder as a reciprocating compressor. In some embodiments a compression check valve system is used to regulate pressure and flow within cylinders of the engine during a compression process.

Rayleigh/Raman/LIF measurements in a turbulent lean premixed combustor

Energy Technology Data Exchange (ETDEWEB)

Nandula, S.P.; Pitz, R.W. [Vanderbilt Univ., Nashville, TN (United States); Barlow, R.S. [Sandia National Labs., Livermore, CA (United States)] [and others

1995-10-01

Much of the industrial electrical generation capability being added worldwide is gas-turbine engine based and is fueled by natural gas. These gas-turbine engines use lean premixed (LP) combustion to meet the strict NO{sub x} emission standards, while maintaining acceptable levels of CO. In conventional, diffusion flame gas turbine combustors, large amount of NO{sub x} forms in the hot stoichiometric zones via the Zeldovich (thermal) mechanism. Hence, lean premixed combustors are rapidly becoming the norm, since they are specifically designed to avoid these hot stoichiometric zones and the associated thermal NO, However, considerable research and development are still required to reduce the NO{sub x} levels (25-40 ppmvd adjusted to 15% O{sub 2} with the current technology), to the projected goal of under 10 ppmvd by the turn of the century. Achieving this objective would require extensive experiments in LP natural gas (or CH{sub 4}) flames for understanding the combustion phenomena underlying the formation of the exhaust pollutants. Although LP combustion is an effective way to control NO{sub x}, the downside is that it increases the CO emissions. The formation and destruction of the pollutants (NO{sub x} and CO) are strongly affected by the fluid mechanics, the finite-rate chemistry, and their (turbulence-chemistry) interactions. Hence, a thorough understanding of these interactions is vital for controlling and reducing the pollutant emissions. The present research is contributing to this goal by providing a detailed nonintrusive laser based data set with good spatial and temporal resolutions of the pollutants (NO and CO) along with the major species, temperature, and OH. The measurements reported in this work, along with the existing velocity data on a turbulent LP combustor burning CH{sub 4}, would provide insight into the turbulence-chemistry interactions and their effect on pollutant formation.

Flashback mechanisms in lean premixed gas turbine combustion

CERN Document Server

Benim, Ali Cemal

2014-01-01

Blending fuels with hydrogen offers the potential to reduce NOx and CO2 emissions in gas turbines, but doing so introduces potential new problems such as flashback.  Flashback can lead to thermal overload and destruction of hardware in the turbine engine, with potentially expensive consequences. The little research on flashback that is available is fragmented. Flashback Mechanisms in Lean Premixed Gas Turbine Combustion by Ali Cemal Benim will address not only the overall issue of the flashback phenomenon, but also the issue of fragmented and incomplete research.Presents a coherent review of f

Evaluation of the physical dew point in the economizer of a combined cycle burning natural gas

Energy Technology Data Exchange (ETDEWEB)

Pena, F.; Blanco, J.M. [Universidad del Pais Vasco/E.H.U. Alameda de Urquijo s/n, Bilbao (Spain). Dpto. Maquinas y Motores Termicos, Escuela Sup. de Ingenieria

2007-08-15

Natural gas contents a considerable percentage of hydrogen, so is obvious to expect an amount of water vapour in its combustion exhaust gases, which would raise the dew point temperature. That means a higher speed of corrosion over the whole exposed physical area, which could represent a serious risk of breakdown, especially in pressurized hot-water equipments. In this work, a new methodology for determining the physical dew point inside a economizer depending on the fuel type burned (in this case is natural gas) has been developed. The calculation of the total amount of condensed water has also been carried out as well as the localization of the area where this condensation occurs. Acid dew point has not been taken into account here although exhaust gases are acidic, due mainly to the low sulphur content which is almost undetectable when burning natural gas, but it will be performed in a later study coming soon. (author)

Turbulent spark-jet ignition in SI gas fuelled engine

Directory of Open Access Journals (Sweden)

Pielecha Ireneusz

2017-01-01

Full Text Available The article contains a thermodynamic analysis of a new combustion system that allows the combustion of stratified gas mixtures with mean air excess coefficient in the range 1.4-1.8. Spark ignition was used in the pre-chamber that has been mounted in the engine cylinder head and contained a rich mixture out of which a turbulent flow of ignited mixture is ejected. It allows spark-jet ignition and the turbulent combustion of the lean mixture in the main combustion chamber. This resulted in a two-stage combustion system for lean mixtures. The experimental study has been conducted using a single-cylinder test engine with a geometric compression ratio ε = 15.5 adapted for natural gas supply. The tests were performed at engine speed n = 2000 rpm under stationary engine load when the engine operating parameters and toxic compounds emissions have been recorded. Analysis of the results allowed to conclude that the evaluated combustion system offers large flexibility in the initiation of charge ignition through an appropriate control of the fuel quantities supplied into the pre-chamber and into the main combustion chamber. The research concluded with determining the charge ignition criterion for a suitably divided total fuel dose fed to the cylinder.

Analysis of Modifications on a Spark Ignition Engine for Operation with Natural Gas

Directory of Open Access Journals (Sweden)

Ramasamy D.

2016-01-01

Full Text Available Transportation is one of the key contributors to petroleum usage and emissions to the atmosphere. According to researchers, there are many ways to use transport by using renewable energy sources. Of these solutions, the immediate solution which requires less modification to current engine technology is by using gaseous fuels. Natural gas is the fuel of choice for minor modification to current engines. As it can be derived from anaerobic digestion process, the potential as a renewable energy source is tremendous, especially for an agricultural country such a Malaysia. The aim in the future will be operating an engine with natural gas only with pipelines straight to houses for easy filling. The fuel is light and can be easily carried in vehicles when in compressed form. As such, Compressed Natural Gas (CNG is currently used in bi-fuel engines, but is mostly not optimized in term of their performance. The focus of the paper is to optimize a model of natural gas engine by one dimensional flow modeling for operation with natural gas. The model is analyzed for performance and emission characteristics produced by a gasoline engine and later compared with natural gas. The average performance drop is about 15% from its gasoline counterpart. The 4% benchmark indicates that the modification to ignition timing and compression ratio does improve engine performance using natural gas as fuel.

Development of a natural gas stratified charge rotary engine

Energy Technology Data Exchange (ETDEWEB)

Sierens, R.; Verdonck, W.

1985-01-01

A water model has been used to determine the positions of separate inlet ports for a natural gas, stratified charge rotary engine. The flow inside the combustion chamber (mainly during the induction period) has been registered by a film camera. From these tests the best locations of the inlet ports have been obtained, a prototype of this engine has been built by Audi NSU and tested in the laboratories of the university of Gent. The results of these tests, for different stratification configurations, are given. These results are comparable with the best results obtained by Audi NSU for a homogeneous natural gas rotary engine.

40 CFR 60.4325 - What emission limits must I meet for NOX if my turbine burns both natural gas and distillate oil...

Science.gov (United States)

2010-07-01

... NOX if my turbine burns both natural gas and distillate oil (or some other combination of fuels)? 60... both natural gas and distillate oil (or some other combination of fuels)? You must meet the emission... burning that fuel. Similarly, when your total heat input is greater than 50 percent distillate oil and...

Characterization of Lean Misfire Limits of Mixture Alternative Gaseous Fuels Used for Spark Ignition Engines

Directory of Open Access Journals (Sweden)

Miqdam Tariq Chaichan

2012-03-01

Full Text Available Increasing on gaseous fuels as clean, economical and abundant fuels encourages the search for optimum conditions of gas-fueled internal combustion engines. This paper presents the experimental results on the lean operational limits of Recardo E6 engine using gasoline, LPG, NG and hydrogen as fuels. The first appearance of almost motoring cycle was used to define the engine lean limit after the fuel flow was reduced gradually. The effects of compression ratio, engine speed and spark timing on the engine operational limits are presented and discussed in detailed. Increasing compression ratio (CR extend the lean limits, this appears obviously with hydrogen, which has a wide range of equivalence ratios, while for hydrocarbon fuel octane number affect gasoline, so it can' t work above CR=9:1, and for LPG it reaches CR=12:1, NG reaches CR=15:1 at lean limit operation. Movement from low speeds to medium speeds extended lean misfire limits, while moving from medium to high speeds contracted the lean misfiring limits. NOx, CO and UBHC concentrations increased with CR increase for all fuels, while CO2 concentrations reduced with this increment. NOx concentration increased for medium speeds and reduced for high speeds, but the resulted concentrations were inconcedrable for these lean limits. CO and CO2 increased with engine speed increase, while UBHC reduced with this increment. The hydrogen engine runs with zero CO, CO2 and UNHC concentrations, and altra low levels of NOx concentrations at studied lean misfire limits

Laser-induced breakdown ignition in a gas fed two-stroke engine

Science.gov (United States)

Loktionov, E. Y.; Pasechnikov, N. A.; Telekh, V. D.

2018-01-01

Laser-induced ignition for internal combustion engines is investigated intensively after demonstration of a compact ‘laser plug’ possibility. Laser spark benefits as compared to traditional spark plugs are higher compression rate, and possibility of almost any fuel ignition, so lean mixtures burning with lower temperatures could reduce harmful exhausts (NO x , CH, etc). No need in electrode and possibility for multi-point, linear or circular ignition can make combustion even more effective. Laser induced combustion wave appears faster and is more stable in time, than electric one, so can be used for ramjets, chemical thrusters, and gas turbines. To the best of our knowledge, we have performed laser spark ignition of a gas fed two-stroke engine for the first time. Combustion temperature and pressure, exhaust composition, ignition timing were investigated at laser and compared to a regular electric spark ignition in a two-stroke model engine. Presented results show possibility for improvement of two-stroke engines performance, in terms of rotation rate increase and NO x emission reduction. Such compact engines using locally mined fuel could be highly demanded in remote Arctic areas.

Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

OpenAIRE

Semin; Abdul R. Ismail; Rosli A. Bakar

2009-01-01

Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

An experimental study of a hydrogen-enriched ethanol fueled Wankel rotary engine at ultra lean and full load conditions

International Nuclear Information System (INIS)

Amrouche, F.; Erickson, P.A.; Varnhagen, S.; Park, J.W.

2016-01-01

Highlights: • H_2 was added at the intake of a single-rotor ethanol fueled Wankel engine. • The engine was operating at ultra-lean condition, WOT and 3000 rpm. • H_2 enrichment helps shortening the burn duration, enhance the thermal efficiency and reduce the BSEC. • H_2 addition helps to reduce HC, CO and CO_2 emissions. - Abstract: In this paper, the effect of hydrogen addition to ethanol in a monorotor Wankel engine at wide open throttle position and in an ultra-lean operating regime was experimentally investigated. For this aim, variation of hydrogen enrichment levels on the ethanol engine performance and emissions were considered. Experiments were carried out under a constant engine speed of 3000 rpm and fixed spark timing of 15 °BTDC. The test results showed that hydrogen enrichment improved the combustion process through shortening of the flame development and flame propagation periods and reducing the cyclic variation. Furthermore, the reduction of burn duration with the increase of hydrogen fraction enhances the thermal efficiency, reducing the brake-specific energy consumption, as well as reducing the unburned hydrocarbons emissions of the Wankel engine.

Particle emissions from compressed natural gas engines

International Nuclear Information System (INIS)

Ristovski, Z.D.; Morawska, L.; Hitchins, J.; Thomas, S.; Greenaway, C.; Gilbert, D.

2000-01-01

This paper presents the results of measurements conducted to determine particle and gas emissions from two large compressed natural gas (CNG) spark ignition (SI) engines. Particle size distributions in the range from 0.01-30 μm, and gas composition were measured for five power settings of the engines: 35, 50, 65, 80 and 100% of full power. Particle emissions in the size range between 0.5 and 30 μm, measured by the aerodynamic particle sizer (APS), were very low at a level below two particles cm -3 . These concentrations were comparable with average ambient concentration, and were not considered in the succeeding analysis. Both engines produce significant amounts of particles in the size range between 0.015 and 0.7 μm, measured by the scanning mobility particle size (SMPS). Maximum number of concentrations of about 1 x 10 7 particles cm -3 were very similar for both engines. The CMDs were in the range between 0.020 and 0.060 μm. The observed levels of particulate emission are in terms of number of the same order as emissions from heavy duty diesel engines (Morawska et al., Environ. Sci. Tech. 32, 2033-2042). On the other hand, emissions of CO and NO x of 5.53 and 3.33 g k W h -1 , respectively, for one of the tested engines, were considerably lower than set by the standards. According to the specifications for the gas emissions, provided by the US EPA (US EPA, 1997), this engine can be considered as a 'low-emission' engine, although emissions of submicrometer particles are of the same order as heavy-duty vehicles. (Author)

Conditioning of data for cyclic variation of IMEP under lean burn operation in a spark-ignition engine; Hibana tenka kikan no kihaku nensho untenji ni okeru zushi heikin yuko atsuryoku no hendo

Energy Technology Data Exchange (ETDEWEB)

Ishii, K.; Urata, Y.; Yoshida, K.; Ono, t. [Honda Motor Co. Ltd., Tokyo (Japan)

1997-07-25

In this study, we investigated the relationship of indicated mean effective pressure (IMEP) for a spark ignition engine under lean combustion with the cyclic variation of mass fraction burned by measuring the energy release from the spark plug, intensity of the light emission from the flame and the cylinder pressure at the same time. In order to minimized an error in the initial and late combustion sages of the mass fraction burned to be obtained by cylinder pressure, spark plug energy and intensity of light emission were measured. As a result, it was found that there are three main causes of cyclic variation of IMEP. These consist of the burning speed during the initial stage of combustion, variation in the total mass fraction burned, and variation of the late burning during the late expansion stroke. Thus, we determined that there is a favorable interrelationship between the IMEPs and the corrected mass fraction burned. 13 refs., 9 figs., 1 tab.

Performance and heat release analysis of a pilot-ignited natural gas engine

Energy Technology Data Exchange (ETDEWEB)

Krishnan, S.R.; Biruduganti, M.; Mo, Y.; Bell, S.R.; Midkiff, K.C. [Alabama Univ., Dept. of Mechanical Engineering, Tuscaloosa, AL (United States)

2002-09-01

The influence of engine operating variables on the performance, emissions and heat release in a compression ignition engine operating in normal diesel and dual-fuel modes (with natural gas fuelling) was investigated. Substantial reductions in NO{sub x} emissions were obtained with dual-fuel engine operation. There was a corresponding increase in unburned hydrocarbon emissions as the substitution of natural gas was increased. Brake specific energy consumption decreased with natural gas substitution at high loads but increased at low loads. Experimental results at fixed pilot injection timing have also established the importance of intake manifold pressure and temperature in improving dual-fuel performance and emissions at part load. (Author)

Advanced Natural Gas Reciprocating Engines(s)

Energy Technology Data Exchange (ETDEWEB)

Zurlo, James [Dresser, Inc., Addison, TX (United States)

2012-04-05

The ARES program was initiated in 2001 to improve the overall brake thermal efficiency of stationary, natural gas, reciprocating engines. The ARES program is a joint award that is shared by Dresser, Inc., Caterpillar and Cummins. The ARES program was divided into three phases; ARES I (achieve 44% BTE), ARES II (achieve 47% BTE) and ARES III (achieve 50% BTE). Dresser, Inc. completed ARES I in March 2005 which resulted in the commercialization of the APG1000 product line. ARES II activities were completed in September 2010 and the technology developed is currently being integrated into products. ARES III activities began in October 2010. The ARES program goal is to improve the efficiency of natural gas reciprocating engines. The ARES project is structured in three phases with higher efficiency goals in each phase. The ARES objectives are as follows: 1. Achieve 44% (ARES I), 47% (ARES II), and 50% brake thermal efficiency (BTE) as a final ARES III objective 2. Achieve 0.1 g/bhp-hr NOx emissions (with after-treatment) 3. Reduce the cost of the produced electricity by 10% 4. Improve or maintain reliability, durability and maintenance costs

Evaluation of the Predictive Capabilities of a Phenomenological Combustion Model for Natural Gas SI Engine

Directory of Open Access Journals (Sweden)

Toman Rastislav

2017-12-01

Full Text Available The current study evaluates the predictive capabilities of a new phenomenological combustion model, available as a part of the GT-Suite software package. It is comprised of two main sub-models: 0D model of in-cylinder flow and turbulence, and turbulent SI combustion model. The 0D in-cylinder flow model (EngCylFlow uses a combined K-k-ε kinetic energy cascade approach to predict the evolution of the in-cylinder charge motion and turbulence, where K and k are the mean and turbulent kinetic energies, and ε is the turbulent dissipation rate. The subsequent turbulent combustion model (EngCylCombSITurb gives the in-cylinder burn rate; based on the calculation of flame speeds and flame kernel development. This phenomenological approach reduces significantly the overall computational effort compared to the 3D-CFD, thus allowing the computation of full engine operating map and the vehicle driving cycles. Model was calibrated using a full map measurement from a turbocharged natural gas SI engine, with swirl intake ports. Sensitivity studies on different calibration methods, and laminar flame speed sub-models were conducted. Validation process for both the calibration and sensitivity studies was concerning the in-cylinder pressure traces and burn rates for several engine operation points achieving good overall results.

Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

Energy Technology Data Exchange (ETDEWEB)

Korakianitis, T.; Namasivayam, A.M.; Crookes, R.J. [School of Engineering and Materials Science, Queen Mary University of London (United Kingdom)

2011-02-15

Natural gas is a fossil fuel that has been used and investigated extensively for use in spark-ignition (SI) and compression-ignition (CI) engines. Compared with conventional gasoline engines, SI engines using natural gas can run at higher compression ratios, thus producing higher thermal efficiencies but also increased nitrogen oxide (NO{sub x}) emissions, while producing lower emissions of carbon dioxide (CO{sub 2}), unburned hydrocarbons (HC) and carbon monoxide (CO). These engines also produce relatively less power than gasoline-fueled engines because of the convergence of one or more of three factors: a reduction in volumetric efficiency due to natural-gas injection in the intake manifold; the lower stoichiometric fuel/air ratio of natural gas compared to gasoline; and the lower equivalence ratio at which these engines may be run in order to reduce NO{sub x} emissions. High NO{sub x} emissions, especially at high loads, reduce with exhaust gas recirculation (EGR). However, EGR rates above a maximum value result in misfire and erratic engine operation. Hydrogen gas addition increases this EGR threshold significantly. In addition, hydrogen increases the flame speed of the natural gas-hydrogen mixture. Power levels can be increased with supercharging or turbocharging and intercooling. Natural gas is used to power CI engines via the dual-fuel mode, where a high-cetane fuel is injected along with the natural gas in order to provide a source of ignition for the charge. Thermal efficiency levels compared with normal diesel-fueled CI-engine operation are generally maintained with dual-fuel operation, and smoke levels are reduced significantly. At the same time, lower NO{sub x} and CO{sub 2} emissions, as well as higher HC and CO emissions compared with normal CI-engine operation at low and intermediate loads are recorded. These trends are caused by the low charge temperature and increased ignition delay, resulting in low combustion temperatures. Another factor is

Natural gas engine concept with EZEV potential; Erdgasmotorkonzept mit EZEV-Potential

Energy Technology Data Exchange (ETDEWEB)

Maier, F.; Mueller, P.; Heck, E.; Langen, P. [BMW AG (Germany)

1997-09-01

The first natural gas vehicles form BMW are designed for arbitrary gasoline or natural gas operation. It is possible only to a limited extent to take advantage of the benefits of natural gas as a fuel as long as this is the case. An analysis was made to determine possible improvements in terms of fuel economy, emissions, full load and maximum exhaust gas temperatures through selective optimisation for exclusive natural gas operation. The results of this analysis have been used in the design of natural gas engines for mid-sized vehicles. Vehicle examinations in FTP75 confirm the existing potential for satisfying EZEV standards discussed in California even with vehicles of the upper midsize category by using optimised natural gas engines. (orig.) [Deutsch] Die ersten Automobile mit Erdgasantrieb von BMW sind fuer den wahlweisen Benzin- oder Erdgasbetrieb ausgelegt. Deshalb koennen die Vorteile des Kraftstoffs Erdgas nur zum Teil genutzt werden. Es wurde untersucht, welche Verbesserungen durch gezielte Optimierung fuer den ausschliesslichen Erdgasbetrieb bei Kraftstoffverbrauch, Emissionen, Vollast und maximalen Abgastemperaturen moeglich sind. Die Ergebnisse wurden bei der Auslegung von Erdgasmotoren fuer Mittelklassefahrzeuge verwendet. Untersuchungen im FTP-75 bestaetigen, dass mit optimierten Erdgasmotoren das Potential besteht, selbst mit Automobilen der oberen Mittelklasse die in Kalifornien diskutierten EZEV-Standards zu erfuellen. (orig.)

Dual-fuelling of a direct-injection automotive diesel engine by diesel and compressed natural gas

International Nuclear Information System (INIS)

Pirouzpanah, V.; Mohammadi Kosha, A.; Mosseibi, A.; Moshirabadi, J.; Gangi, A.; Moghadaspour, M.

2000-01-01

Application of Compressed Natural Gas in diesel engines has always been important, especially in the field of automotive engineering. This is due to easy accessibility, better mixing quality and good combustion characteristics of the Compressed Natural Gas fuel. In this study the application of Compressed Natural Gas fuel along with diesel oil in a heavy duty direct-injection automotive diesel engine is experimentally investigated. In order to convert a diesel engine into a diesel-gas one, the so called m ixed diesel-gas a pproach has been used and for this purpose a carbureted Compressed Natural Gas fuel system has been designed and manufactured. For controlling quantity of Compressed Natural Gas, the gas valve is linked to the diesel fuel injection system by means of a set of rods. Then, the dual-fuel system is adjusted so that, at full load conditions, the quantity of diesel fuel is reduced to 20% and 80% of its equivalent energy is substituted by Compressed Natural Gas fuel. Also injection pressure of pilot jet is increased by 11.4%. Performance and emission tests are conducted under variation of load and speed on both diesel and diesel-gas engines. Results show that, with equal power and torque, the diesel-gas engine has the potential to improve overall engine performance and emission. For example, at rated power and speed, fuel economy increases by 5.48%, the amount of smoke decreases by 78%, amount of CO decreases by 64.3% and mean exhaust gas temperature decreases by 6.4%

Pressure-time characteristics in diesel engine fueled with natural gas

Energy Technology Data Exchange (ETDEWEB)

Selim, Mohamed Y.E. [Helwan Univ., Mechanical Power Engineering Dept., Cairo (Egypt)

2001-04-01

Combustion pressure data are measured and presented for a dual fuel engine running on dual fuel of diesel and compressed natural gas, and compared to the diesel engine case. The maximum pressure rise rate during combustion is presented as a measure of combustion noise. Experimental investigation on diesel and dual fuel engines revealed the noise generated from combustion in both cases. A Ricardo E6 diesel version engine is converted to run on dual fuel of diesel and compressed natural gas and is used throughout the work. The engine is fully computerized and the cylinder pressure data, crank angle data are stored in a PC for off-line analysis. The effect of engine speeds, loads, pilot injection angle, and pilot fuel quantity on combustion noise is examined for both diesel and dual engine. Maximum pressure rise rate and some samples of ensemble averaged pressure-crank angle data are presented in the present work. The combustion noise, generally, is found to increase for the dual fuel engine case as compared to the diesel engine case. (Author)

Fuels Containing Methane of Natural Gas in Solution

Science.gov (United States)

Sullivan, Thomas A.

2004-01-01

While exploring ways of producing better fuels for propulsion of a spacecraft on the Mars sample return mission, a researcher at Johnson Space Center (JSC) devised a way of blending fuel by combining methane or natural gas with a second fuel to produce a fuel that can be maintained in liquid form at ambient temperature and under moderate pressure. The use of such a blended fuel would be a departure for both spacecraft engines and terrestrial internal combustion engines. For spacecraft, it would enable reduction of weights on long flights. For the automotive industry on Earth, such a fuel could be easily distributed and could be a less expensive, more efficient, and cleaner-burning alternative to conventional fossil fuels. The concept of blending fuels is not new: for example, the production of gasoline includes the addition of liquid octane enhancers. For the future, it has been commonly suggested to substitute methane or compressed natural gas for octane-enhanced gasoline as a fuel for internal-combustion engines. Unfortunately, methane or natural gas must be stored either as a compressed gas (if kept at ambient temperature) or as a cryogenic liquid. The ranges of automobiles would be reduced from their present values because of limitations on the capacities for storage of these fuels. Moreover, technical challenges are posed by the need to develop equipment to handle these fuels and, especially, to fill tanks acceptably rapidly. The JSC alternative to provide a blended fuel that can be maintained in liquid form at moderate pressure at ambient temperature has not been previously tried. A blended automotive fuel according to this approach would be made by dissolving natural gas in gasoline. The autogenous pressure of this fuel would eliminate the need for a vehicle fuel pump, but a pressure and/or flow regulator would be needed to moderate the effects of temperature and to respond to changing engine power demands. Because the fuel would flash as it entered engine

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

Energy Technology Data Exchange (ETDEWEB)

Victor W. Wong; Tian Tian; Grant Smedley; Jeffrey Jocsak

2004-09-30

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. An iterative process of simulation, experimentation and analysis, are being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and ring-design concepts have been explored, and engine experiments have been done on a full-scale Waukesha VGF F18 in-line 6 cylinder power generation engine rated at 370 kW at 1800 rpm. Current accomplishments include designing and testing ring-packs using a subtle top-compression-ring profile (skewed barrel design), lowering the tension of the oil-control ring, employing a negative twist to the scraper ring to control oil consumption. Initial test data indicate that piston ring-pack friction was reduced by 35% by lowering the oil-control ring tension alone, which corresponds to a 1.5% improvement in fuel efficiency. Although small in magnitude, this improvement represents a first step towards anticipated aggregate improvements from other strategies. Other ring-pack design strategies to lower friction have been identified, including reduced axial distance between the top two rings, tilted top-ring groove. Some of these configurations have been tested and some await further evaluation. Colorado State University performed the tests and Waukesha Engine Dresser, Inc. provided technical support. Key elements of the continuing work include optimizing the engine piston design, application of surface and material developments in conjunction with improved lubricant properties, system modeling and analysis, and continued technology

Hybrid Automotive Engine Using Ethanol-Burning Miller Cycle

Science.gov (United States)

Weinstein, Leonard

2004-01-01

A proposed hybrid (internal-combustion/ electric) automotive engine system would include as its internal-combustion subsystem, a modified Miller-cycle engine with regenerative air preheating and with autoignition like that of a Diesel engine. The fuel would be ethanol and would be burned lean to ensure complete combustion. Although the proposed engine would have a relatively low power-to-weight ratio compared to most present engines, this would not be the problem encountered if this engine were used in a non-hybrid system since hybrid systems require significantly lower power and thus smaller engines than purely internal-combustion-engine-driven vehicles. The disadvantage would be offset by the advantages of high fuel efficiency, low emission of nitrogen oxides and particulate pollutants, and the fact that ethanol is a renewable fuel. The original Miller-cycle engine, named after its inventor, was patented in the 1940s and is the basis of engines used in some modern automobiles, but is not widely known. In somewhat oversimplified terms, the main difference between a Miller-cycle engine and a common (Otto-cycle) automobile engine is that the Miller-cycle engine has a longer expansion stroke while retaining the shorter compression stroke. This is accomplished by leaving the intake valve open for part of the compression stroke, whereas in the Otto cycle engine, the intake valve is kept closed during the entire compression stroke. This greater expansion ratio makes it possible to extract more energy from the combustion process without expending more energy for compression. The net result is greater efficiency. In the proposed engine, the regenerative preheating would be effected by running the intake air through a heat exchanger connected to the engine block. The regenerative preheating would offer two advantages: It would ensure reliable autoignition during operation at low ambient temperature and would help to cool the engine, thereby reducing the remainder of the

Particulate Matter Emission from Dual Fuel Diesel Engine Fuelled with Natural Gas

Directory of Open Access Journals (Sweden)

Stelmasiak Zdzisław

2017-06-01

Full Text Available The paper presents the results of examination of particulate matter emission from the Diesel engine FPT 1.3 MJT simultaneously fuelled with diesel oil and natural gas CNG. The basic premise for engine adaptation was the addition of a small amount of CNG to reduce exhaust gas opacity and particulate matter emission. At this assumption, diesel oil remained the basic fuel, with contribution amounting to 0,70-0,85 of total energy delivered to the engine. The dual fuel engine was examined using an original controller installed in the Diesel engine FPT 1.3 MJT which controlled the diesel fuel dose. The dose of the injected natural gas was controlled by changing the opening time of gas injectors at constant pressure in the gas collector. The examined issues included the exhaust gas opacity, and the total number and fractional distribution of the emitted particles. The measurements were performed at twenty selected measuring points corresponding to the New European Driving Cycle (NEDC test. The performed tests have demonstrated a positive effect of gas addition on exhaust gas opacity and particulate matter emission. Depending on test conditions, the exhaust gas opacity was reduced by 10÷92%, and the total number of particles by 30÷40%. The performed tests have revealed that a small addition of gas can reduce the load of the DPF filter, extend its lifetime, and increase engine reliability. Longer time intervals between successive DPF filter regenerations improve ecological properties of the engine.

Experimental study on the natural gas dual fuel engine test and the higher the mixture ratio of hydrogen to natural gas

Energy Technology Data Exchange (ETDEWEB)

Kim, B.S.; Lee, Y.S.; Park, C.K. [Cheonnam University, Kwangju (Korea); Masahiro, S. [Kyoto University, Kyoto (Japan)

1999-05-28

One of the unsolved problems of the natural gas dual fuel engine is that there is too much exhaust of Total Hydrogen Carbon(THC) at a low equivalent mixture ratio. To fix it, a natural gas mixed with hydrogen was applied to engine test. The results showed that the higher the mixture ratio of hydrogen to natural gas, the higher the combustion efficiency. And when the amount of the intake air is reached to 90% of WOT, the combustion efficiency was promoted. But, like a case making the injection timing earlier, the equivalent mixture ratio for the nocking limit decreases and the produce of NOx increases. 5 refs., 9 figs., 1 tab.

Internal combustion engine for natural gas compressor operation

Energy Technology Data Exchange (ETDEWEB)

Hagen, Christopher L.; Babbitt, Guy; Turner, Christopher; Echter, Nick; Weyer-Geigel, Kristina

2016-04-19

This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a system for compressing a gas comprises a reciprocating internal combustion engine including at least one piston-cylinder assembly comprising a piston configured to travel in a cylinder and to compress gas in the cylinder in multiple compression stages. The system can further comprise a first pressure tank in fluid communication with the piston-cylinder assembly to receive compressed gas from the piston-cylinder assembly until the first pressure tank reaches a predetermined pressure, and a second pressure tank in fluid communication with the piston-cylinder assembly and the first pressure tank. The second pressure tank can be configured to receive compressed gas from the piston-cylinder assembly until the second pressure tank reaches a predetermined pressure. When the first and second pressure tanks have reached the predetermined pressures, the first pressure tank can be configured to supply gas to the piston-cylinder assembly, and the piston can be configured to compress the gas supplied by the first pressure tank such that the compressed gas flows into the second pressure tank.

Assessment of Methane Emissions – Impact of Using Natural Gas Engines in Unconventional Resource Development

Energy Technology Data Exchange (ETDEWEB)

Nix, Andrew [West Virginia Univ., Morgantown, WV (United States); Johnson, Derek [West Virginia Univ., Morgantown, WV (United States); Heltzel, Robert [West Virginia Univ., Morgantown, WV (United States); Oliver, Dakota [West Virginia Univ., Morgantown, WV (United States)

2018-04-08

Researchers at the Center for Alternative Fuels, Engines, and Emissions (CAFEE) completed a multi-year program under DE-FE0013689 entitled, “Assessing Fugitive Methane Emissions Impact Using Natural Gas Engines in Unconventional Resource Development.” When drilling activity was high and industry sought to lower operating costs and reduce emissions they began investing in dual fuel and dedicated natural gas engines to power unconventional well equipment. From a review of literature we determined that the prime-movers (or major fuel consumers) of unconventional well development were the service trucks (trucking), horizontal drilling rig (drilling) engines, and hydraulic stimulation pump (fracturing) engines. Based on early findings from on-road studies we assessed that conversion of prime movers to operate on natural gas could contribute to methane emissions associated with unconventional wells. As such, we collected significant in-use activity data from service trucks and in-use activity, fuel consumption, and gaseous emissions data from drilling and fracturing engines. Our findings confirmed that conversion of the prime movers to operate as dual fuel or dedicated natural gas – created an additional source of methane emissions. While some gaseous emissions were decreased from implementation of these technologies – methane and CO2 equivalent emissions tended to increase, especially for non-road engines. The increases were highest for dual fuel engines due to methane slip from the exhaust and engine crankcase. Dedicated natural gas engines tended to have lower exhaust methane emissions but higher CO2 emissions due to lower efficiency. Therefore, investing in currently available natural gas technologies for prime movers will increase the greenhouse gas footprint of the unconventional well development industry.

40 CFR 1048.620 - What are the provisions for exempting large engines fueled by natural gas or liquefied petroleum...

Science.gov (United States)

2010-07-01

... large engines fueled by natural gas or liquefied petroleum gas? 1048.620 Section 1048.620 Protection of... exempting large engines fueled by natural gas or liquefied petroleum gas? (a) If an engine meets all the... natural gas or liquefied petroleum gas. (2) The engine must have maximum engine power at or above 250 kW...

Operation experiences of landfill gas engines; Motorer foer deponigas - Tillgaenglighet och drifterfarenheter

Energy Technology Data Exchange (ETDEWEB)

Dejfors, Charlotte; Grimberger, Goeran [AaF-Energikonsult Stockholm AB (Sweden)

2000-06-01

The gas that is obtained from landfilled waste is produced by bacteria that digest organic material in an anaerobic environment. Landfill gas consists mainly of methane, carbon dioxide and water vapour. It may be used either as auxiliary fuel in boilers close to the landfill or to generate electricity by means of a gas engine. Several plants where landfill gas is used in gas engines have had serious problems, a. o. with burned exhaust valves. These problems may occur already after a short period of operation, which influences the profitability. The purposes of the project reported were to collect operational experience in Sweden with engines using landfill gas as fuel, to identify which problems there are and which actions or improvements have been implemented in order to correct for these problems. Today, there are 9 facilities where landfill gas is used to fuel a total of 13 gas engines. In addition, there is an engine in Goeteborg which has scarcely been in operation after its installation because there is not enough gas. Contact has been taken with all these facilities. Many have pointed out that the gas engines are sensitive in the vicinity of maximum load, where the control system requires an even gas flow and a stable composition of the gas. A counter-measure in the facilities is to avoid running the engine at full load. All engines are equipped with a lean-NO{sub x} system in order to minimise NO{sub x} emissions. Many have remarked that the lean-NO{sub x} system shuts the engine off when emissions exceed the allowed limits. There is a consensus that spark plugs and ignition cables have created operational problems. These have been changed more frequently than originally expected. Another problem, which has caused operational problems and a need for maintenance, is deposits mainly in the combustion chamber, in valves and cylinder heads. Deposits and high exhaust gas temperature have led to burnt exhaust gas valves and cylinder heads on half of the engines

Session 4: On-board exhaust gas reforming for improved performance of natural gas HCCI engines

Energy Technology Data Exchange (ETDEWEB)

Amieiro, A.; Golunski, S.; James, D. [Johnson Matthey Technology Centre, Sonning Common, Reading (United Kingdom); Miroslaw, Wyszynski; Athanasios, Megaritis; Peucheret, S. [Birmingham Univ., School of Engineering, Future Power Systems Research Group (United Kingdom); Hongming, Xu [Jaguar Cars Ltd, W/2/021 Engineering Centre, Whitley, Coventry (United Kingdom)

2004-07-01

Although natural gas (NG) is a non-renewable energy source, it is still a very attractive alternative fuel for transportation - it is inexpensive, abundant, and easier to refine than petroleum. Unfortunately the minimum spark energy required for NG ignition is higher than for liquid fuels, and engine performance is reduced since the higher volume of NG limits the air breathing capacity of the cylinders. On the other hand, the flammability range of NG is wider than for other hydrocarbons, so the engine can operate under leaner conditions. Environmentally, the use of NG is particularly attractive since it has a low flame temperature (resulting in reduced NO{sub x} emissions) and a low carbon content compared to diesel or gasoline (resulting in less CO, CO{sub 2} and particulate). In addition, NG is easily made sulphur-free, and has a high octane rating (RON = 110-130) which makes it suitable for high compression engine applications. Exhaust gas recirculation (EGR) into an engine is known to reduce both flame temperature and speed, and therefore produce lower NO{sub x} emissions. In general, a given volume of exhaust gas has a greater effect on flame speed and NO{sub x} emissions than the same quantity of excess air, although there is a limit to the amount of exhaust gas recirculation that can be used without inhibiting combustion. However, hydrogen addition to exhaust gas recirculation has been proved to reduce emissions while increasing flame speed, so improving both the emissions and the thermal efficiency of the engine. On-board reforming of some of the fuel, by reaction with exhaust gas during EGR, is a novel way of adding hydrogen to an engine. We have carried out reforming tests on mixtures of natural gas and exhaust gas at relatively low temperatures (400-600 C), to mimic the low availability of external heat within the integrated system. The reforming catalyst is a nickel-free formulation, containing precious metals promoted by metal oxides. The roles of

Evaluation of process costs for small-scale nitrogen removal from natural gas. Topical report, January 1989-December 1989

International Nuclear Information System (INIS)

Echterhoff, L.W.; Pathak, V.K.

1991-08-01

The report establishes the cost of producing pipeline quality gas on a small scale from high nitrogen subquality natural gas. Three processing technologies are evaluated: cryogenic, Nitrotec Engineering Inc.'s pressure swing adsorption (PSA), and lean oil absorption. Comparison of the established costs shows that the cryogenic process exhibits the lowest total plant investment for nitrogen feed contents up to about 22%, above which the PSA process exhibits the lowest investment cost. The lean oil process exhibits the highest total plant investment at the 25% nitrogen feed studied. Opposite to the total plant investment for the cryogenic process, the total plant investment for the PSA process decreases with increasing nitrogen content primarily due to increasing product gas compression requirements. The cryogenic process exhibits the lowest gas processing costs for the nitrogen content range under study. However, the difference between the gas processing costs for the PSA and cryogenic processes narrows as the nitrogen content approaches 15-25%. The lean oil gas processing cost is very high compared to both the cryogenic and PSA processes. The report verifies that nitrogen removal from natural gas is expensive, especially for small-scale applications, and several avenues are identified for improving the cryogenic and PSA technologies

Final report on 9 kW Stirling Engine for biogas and natural gas

DEFF Research Database (Denmark)

Carlsen, Henrik; Bovin, Jonas Kabell

2001-01-01

The need for a simple and robust engine for natural gas and low quality gas has resulted in the design of a single cylinder, hermetic Stirling engine, which has an electric power output of 9 kW. Two engines have been built. One engine is intended for natural gas as fuel and the other is intended...... eliminates guiding forces on the pistons and the need for X-heads. Grease lubricated needle and ball bearings are used in the kinematic crank mechanism in order to avoid oil penetrating into the cylinder volumes. Working gas is Helium at 8 MPa mean pressure. The engine produce up to 11 kW of shaft power...... corresponding to approximately 10 kW of electric power. The design target was an efficiency of 26 % based on lower heat content of the gas to electricity, but only 24% were obtained. The decrease of efficiency is caused by inhomogeneous capacity flows in the air preheater and insufficient insulation...

Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

Science.gov (United States)

Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

2012-02-21

The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

Combustion and emission characteristics of a natural gas-fueled diesel engine with EGR

International Nuclear Information System (INIS)

Abdelaal, M.M.; Hegab, A.H.

2012-01-01

Highlights: ► An existed DI diesel engine has been modified to suit dual fuel operation with EGR. ► Comparative study has been conducted between different operating modes. ► Dual fuel mode exhibits better performance at high loads than diesel. ► Dual fuel mode exhibits lower NOx and higher HC emissions than diesel. ► EGR improves performance at part loads and emissions of dual fuel mode. - Abstract: The use of natural gas as a partial supplement for liquid diesel fuel is a very promising solution for reducing pollutant emissions, particularly nitrogen oxides (NOx) and particulate matters (PM), from conventional diesel engines. In most applications of this technique, natural gas is inducted or injected in the intake manifold to mix uniformly with air, and the homogenous natural gas–air mixture is then introduced to the cylinder as a result of the engine suction. This type of engines, referred to as dual-fuel engines, suffers from lower thermal efficiency and higher carbon monoxide (CO) and unburned hydrocarbon (HC) emissions; particularly at part load. The use of exhaust gas recirculation (EGR) is expected to partially resolve these problems and to provide further reduction in NOx emission as well. In the present experimental study, a single-cylinder direct injection (DI) diesel engine has been properly modified to run on dual-fuel mode with natural gas as a main fuel and diesel fuel as a pilot, with the ability to employ variable amounts of EGR. Comparative results are given for various operating modes; conventional diesel mode, dual-fuel mode without EGR, and dual-fuel mode with variable amounts of EGR, at different operating conditions; revealing the effect of utilization of EGR on combustion process and exhaust emission characteristics of a pilot ignited natural gas diesel engine.

Effect of water injection on nitric oxide emissions of a gas turbine combustor burning natural gas fuel

Science.gov (United States)

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not.

Characterization of Swirl-Venturi Lean Direct Injection Designs for Aviation Gas-Turbine Combustion

Science.gov (United States)

Heath, Christopher M.

2013-01-01

Injector geometry, physical mixing, chemical processes, and engine cycle conditions together govern performance, operability and emission characteristics of aviation gas-turbine combustion systems. The present investigation explores swirl-venturi lean direct injection combustor fundamentals, characterizing the influence of key geometric injector parameters on reacting flow physics and emission production trends. In this computational study, a design space exploration was performed using a parameterized swirl-venturi lean direct injector model. From the parametric geometry, 20 three-element lean direct injection combustor sectors were produced and simulated using steady-state, Reynolds-averaged Navier-Stokes reacting computations. Species concentrations were solved directly using a reduced 18-step reaction mechanism for Jet-A. Turbulence closure was obtained using a nonlinear ?-e model. Results demonstrate sensitivities of the geometric perturbations on axially averaged flow field responses. Output variables include axial velocity, turbulent kinetic energy, static temperature, fuel patternation and minor species mass fractions. Significant trends have been reduced to surrogate model approximations, intended to guide future injector design trade studies and advance aviation gas-turbine combustion research.

Combustion characteristics of compressed natural gas/diesel dual-fuel turbocharged compressed ignition engine

Energy Technology Data Exchange (ETDEWEB)

Shenghua, L.; Longbao, Z.; Ziyan, W.; Jiang, R. [Xi' an Jiaotong Univ. (China). Dept. of Automotive Engineering

2003-09-01

The combustion characteristics of a turbocharged natural gas and diesel dual-fuelled compression ignition (CI) engine are investigated. With the measured cylinder pressures of the engine operated on pure diesel and dual fuel, the ignition delay, effects of pilot diesel and engine load on combustion characteristics are analysed. Emissions of HC, CO, NO{sub x} and smoke are measured and studied too. The results show that the quantity of pilot diesel has important effects on the performance and emissions of a dual-fuel engine at low-load operating conditions. Ignition delay varies with the concentration of natural gas. Smoke is much lower for the developed dual-fuel engine under all the operating conditions. (Author)

The Impact of Legislation on Gas Can- and Mattress-Related Burn Injuries.

Science.gov (United States)

Kellogg, Levi; Butcher, Brandon; Peek-Asa, Corinne; Wibbenmeyer, Lucy

2018-01-01

Burn prevention program success requires thorough evaluation of intervention outcomes. The impact of 2 engineering-specific burn prevention regulations, the Children's Gasoline Burn Prevention Act and the Standard for the Flammability of Mattress Sets, will be assessed. Records from 1997 to 2015 within the Consumer Product Safety Commission's (CPSC) National Electronic Injury Surveillance System (NEISS) were reviewed. After identifying gas can- and mattress-involved burn injuries, injury incidence was estimated by utilizing survey sampling weights associated with each record. Logistic regression, incorporating estimated injury incidence and adjusting for gender and age, was performed to test for change in injury risk following these regulations. Within NEISS, there were 493 burns involving gas cans, yielding an estimated 19,339 injuries (95% confidence interval [CI], 15,781-22,896) during the 19-year study period. The odds of a gas can burn injury after legislation decreased by 67% for children younger than 5 years (odds ratio [OR], 0.33; 95% CI, 0.16-0.66; P = 0.0018). There was no significant change in risk for persons 5 years and older (OR, 1.07; 95% CI, 0.80-1.41; P = 0.66). During the same time, there were 219 NEISS burns involving mattresses, yielding an estimated 6864 injuries (95% CI, 5071-8658). The odds of a mattress burn injury following legislation enactment decreased by 31% for all ages (OR, 0.69; 95% CI, 0.51-0.94; P = 0.02). Both regulations decreased the odds of injury in their target populations. This study demonstrates that passive interventions involving engineering standards remain a powerful tool for burn prevention and should be the focus of future efforts to improve burn care.

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

Energy Technology Data Exchange (ETDEWEB)

Pratapas, John; Mather, Daniel; Kozlovsky, Anton

2013-03-31

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

Performance and Economics of Catalytic Glow Plugs and Shields in Direct Injection Natural Gas Engines for the Next Generation Natural Gas Vehicle Program: Final Report

Energy Technology Data Exchange (ETDEWEB)

Mello, J. P.; Bezaire, D.; Sriramulu, S.; Weber, R.

2003-08-01

Subcontractor report details work done by TIAX and Westport to test and perform cost analysis for catalytic glow plugs and shields for direct-injection natural gas engines for the Next Generation Natural Gas Vehicle Program.

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME

Energy Technology Data Exchange (ETDEWEB)

John Pratapas; Daniel Mather; Anton Kozlovsky

2007-03-31

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen's significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an

Lean engineering education driving content and competency mastery

CERN Document Server

Flumerfelt, Shannon

2015-01-01

Recent studies by professional organizations devoted to engineering education, such as Vision 2030 (ASME) and Vision 2025 (ASCE), highlight the need for the restructuring of engineering education. Deficiencies of many engineering graduates include poor systems thinking and systems analysis skills, lack of sensitivity for sustainability issues, poorly developed problem solving skills and lack of training to work in (multi- disciplinary) teams, as well as a lack of leadership, entrepreneurship, innovation, and project management skills. The book's contents include an analysis of current shortfalls in engineering education and education related to professional practice in engineering. Further, the authors describe desirable improvements as well as advocacy for the use of lean tenets and tools to create a new future for engineering education. This book presents, for the first time, an outside-in lean engineering perspective of how this commonly accepted and widely practiced and adapted engineering perspecti...

Modeling and simulation of combustion dynamics in lean-premixed swirl-stabilized gas-turbine engines

Science.gov (United States)

Huang, Ying

This research focuses on the modeling and simulation of combustion dynamics in lean-premixed gas-turbines engines. The primary objectives are: (1) to establish an efficient and accurate numerical framework for the treatment of unsteady flame dynamics; and (2) to investigate the parameters and mechanisms responsible for driving flow oscillations in a lean-premixed gas-turbine combustor. The energy transfer mechanisms among mean flow motions, periodic motions and background turbulent motions in turbulent reacting flow are first explored using a triple decomposition technique. Then a comprehensive numerical study of the combustion dynamics in a lean-premixed swirl-stabilized combustor is performed. The analysis treats the conservation equations in three dimensions and takes into account finite-rate chemical reactions and variable thermophysical properties. Turbulence closure is achieved using a large-eddy-simulation (LES) technique. The compressible-flow version of the Smagorinsky model is employed to describe subgrid-scale turbulent motions and their effect on large-scale structures. A level-set flamelet library approach is used to simulate premixed turbulent combustion. In this approach, the mean flame location is modeled using a level-set G-equation, where G is defined as a distance function. Thermophysical properties are obtained using a presumed probability density function (PDF) along with a laminar flamelet library. The governing equations and the associated boundary conditions are solved by means of a four-step Runge-Kutta scheme along with the implementation of the message passing interface (MPI) parallel computing architecture. The analysis allows for a detailed investigation into the interaction between turbulent flow motions and oscillatory combustion of a swirl-stabilized injector. Results show good agreement with an analytical solution and experimental data in terms of acoustic properties and flame evolution. A study of flame bifurcation from a stable

Simulation of lean premixed turbulent combustion

International Nuclear Information System (INIS)

Bell, J; Day, M; Almgren, A; Lijewski, M; Rendleman, C; Cheng, R; Shepherd, I

2006-01-01

There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels such as hydrogen or syngas. Lean premixed systems have the potential to burn these types of fuels with high efficiency and low NOx emissions due to reduced burnt gas temperatures. Although traditional Scientific approaches based on theory and laboratory experiment have played essential roles in developing our current understanding of premixed combustion, they are unable to meet the challenges of designing fuel-flexible lean premixed combustion devices. Computation, with its ability to deal with complexity and its unlimited access to data, has the potential for addressing these challenges. Realizing this potential requires the ability to perform high fidelity simulations of turbulent lean premixed flames under realistic conditions. In this paper, we examine the specialized mathematical structure of these combustion problems and discuss simulation approaches that exploit this structure. Using these ideas we can dramatically reduce computational cost, making it possible to perform high-fidelity simulations of realistic flames. We illustrate this methodology by considering ultra-lean hydrogen flames and discuss how this type of simulation is changing the way researchers study combustion

Survey report for fiscal 1998 on the conversion of the existing coal burning power plant to natural gas burning plant in Sakhalin State; 1998 nendo Saharinshu muke, kisetsu sekitandaki hatsuden no tennen gas daki tenkan chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The present survey is intended to discuss a modernization plan effective in reducing greenhouse effect gases for the two existing coal burning power plants in Sakhalin Island, Sakhalin State, the Federal Republic of Russia. The power plants are Sakhalinskaya Power Plant (GRES) and Yuzhno Sakalinskaya Power Plant (TETs-1). Simultaneously with converting the fuel from coal to natural gas, discussions are given on an optimal plan including introduction of the combined cycle and repowering technologies aiming at improving the thermal efficiency. Reduction in greenhouse effect gases, finance, and economy are evaluated. At the same time, verification will be given on environment improvement in Sakhalin Island, and influence on sustainable economic and social activation. The GRES modernization plan intends to build four combined cycle units each of 80 MW class to have nearly the same total capacity as the current total power generation facility capacity (315 MW). The TETs-1 modernization plan will convert the fuel for the existing boilers from coal to natural gas, modify one of the boilers whose construction is being suspended into gas burning boiler, and add gas turbines. (NEDO)

Gas chromatographic determination of Di-n-butyl phosphate in radioactive lean organic solvent of FBTR carbide fuel reprocessing

International Nuclear Information System (INIS)

Velavendan, P.; Ganesh, S.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2011-01-01

In the present work Di-n- butyl phosphate (DBP) a degraded product of Tri-n-butyl phosphate (TBP) formed by acid hydrolysis and radiolysis in the PUREX process was analyzed. Lean organic streams of different fuel burn-up FBTR carbide fuel reprocessing solution was determined by standard Gas Chromatographic technique. The method involves the conversion of non-volatile Di-n-butyl phosphate into volatile and stable derivatives by the action of diazomethane and then determined by Gas Chromatograph (GC). A calibration graph was made for DBP concentration range of 200-2000 ppm with correlation coefficient of 0.99587 and RSD 1.2 %. (author)

Methane-bomb natural gas

International Nuclear Information System (INIS)

Anon.

1993-01-01

About 50% of the so-called 'greenhouse-effect' is not caused by CO 2 , but by more dangerous gases, among them is methane. Natural gas consists to about 98% of methane. In Austria result about 15% of the methane emissions from offtake, storage, transport (pipelines) and distribution from natural gas. A research study of the Research Centre Seibersdorf points out that between 2.5% and 3.6% of the employed natural gas in Austria emits. The impact of this emitted methane is about 29 times worse than the impact of CO 2 (caused for examples by petroleum burning). Nevertheless the Austrian CO 2 -commission states that an increasing use of natural gas would decrease the CO 2 -emissions - but this statement is suspected to be based on wrong assumptions. (blahsl)

Dual-fuel natural gas/diesel engines: Technology, performance, and emissions

Science.gov (United States)

Turner, S. H.; Weaver, C. S.

1994-11-01

An investigation of current dual-fuel natural gas/diesel engine design, performance, and emissions was conducted. The most pressing technological problems associated with dual-fuel engine use were identified along with potential solutions. It was concluded that dual-fuel engines can achieve low NO(sub x) and particulate emissions while retaining fuel-efficiency and BMEP levels comparable to those of diesel engines. The investigation also examined the potential economic impact of dual-fuel engines in diesel-electric locomotives, marine vessels, farm equipment, construction, mining, and industrial equipment, and stand-alone electricity generation systems. Recommendations for further additional funding to support research, development, and demonstration in these applications were then presented.

Limits of mixture dilution in gas engines

NARCIS (Netherlands)

Doosje, E.

2010-01-01

Natural gas engines find application in transport as well as for stationary power generation. These engines have a lower efficiency compared to the most widely used power plant, the diesel engine, however engines running on natural gas also have some distinct advantages. Gas engines that are

Cycle-by-cycle exhaust temperature monitoring for detection of misfiring and combustion instability in reciprocating natural gas engines

Energy Technology Data Exchange (ETDEWEB)

Gardiner, D.P. [Nexum Research Corp., Kingston, ON (Canada); Bardon, M.F. [Royal Military Coll. of Canada, Kingston, ON (Canada). Dept. of Mechanical Engineering

2007-07-01

The effectiveness of a cycle-by-cycle exhaust temperature monitoring system on engines operating at or near their fully rate load capacity was examined. Tests were conducted on stationary industrial natural gas engines. The study evaluated the monitoring system's ability to detect isolated single misfires, as well as combustion instability during misfire-free operations when the air/fuel ratio of the engine was adjusted to progressively lower settings. The combustion instability level of the engines was quantified by determining the relative variability of the groups of consecutive cycles. The coefficient of variation of indicated mean effective pressure (COV of IMEP) was used to examine cyclic variability. A combustion instability index was used to quantify cyclic variability with cycle-by-cycle exhaust temperature monitoring. Two engines were tested, notably a Cummins QSK 19G turbocharged natural gas engine; and a Waukesha VHP L5790G industrial natural gas engine. The tests demonstrated that cycle-by-cycle exhaust temperature monitoring system was capable of detecting misfiring and combustion instabilities in natural gas engines. 6 refs., 9 figs.

Agile and lean principles and systems engineering: a synergy?

CSIR Research Space (South Africa)

Joseph-Malherbe, SM

2011-09-01

Full Text Available not efficient and effective enough to support rapid fielding of products. The objective of this piece of work is multi-fold: (1) to explore and present fundamental Systems Engineering, Agile and Lean principles (2) the evolution or lack of Lean and Agile...

Evaluation of Knock Behavior for Natural Gas - Gasoline Blends in a Light Duty Spark Ignited Engine

Energy Technology Data Exchange (ETDEWEB)

Pamminger, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Sevik, James [Argonne National Lab. (ANL), Argonne, IL (United States); Scarcelli, Riccardo [Argonne National Lab. (ANL), Argonne, IL (United States); Wallner, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Wooldridge, Steven [Ford Motor Co., Detroit, MI (United States); Boyer, Brad [Ford Motor Co., Detroit, MI (United States); Hall, Carrie M. [Illinois Inst. of Technology, Chicago, IL (United States)

2016-10-17

The compression ratio is a strong lever to increase the efficiency of an internal combustion engine. However, among others, it is limited by the knock resistance of the fuel used. Natural gas shows a higher knock resistance compared to gasoline, which makes it very attractive for use in internal combustion engines. The current paper describes the knock behavior of two gasoline fuels, and specific incylinder blend ratios with one of the gasoline fuels and natural gas. The engine used for these investigations is a single cylinder research engine for light duty application which is equipped with two separate fuel systems. Both fuels can be used simultaneously which allows for gasoline to be injected into the intake port and natural gas to be injected directly into the cylinder to overcome the power density loss usually connected with port fuel injection of natural gas. Adding natural gas at wide open throttle helps to reduce knock mitigating measures and increases the efficiency and power density compared to the other gasoline type fuels with lower knock resistance. The used methods, knock intensity and number of pressure waves, do not show significant differences in knock behavior for the natural gas - gasoline blends compared to the gasoline type fuels. A knock integral was used to describe the knock onset location of the fuels tested. Two different approaches were used to determine the experimental knock onset and were compared to the knock onset delivered by the knock integral (chemical knock onset). The gasoline type fuels show good agreement between chemical and experimental knock onset. However, the natural gas -gasoline blends show higher discrepancies comparing chemical and experimental knock onset.

General Motors natural gas vehicle initiatives

International Nuclear Information System (INIS)

Weber, J.; Koplow, M.D.

1992-01-01

General Motors (GM) has a number of natural gas vehicle (NGV) programs in progress that address various marketing, technical, and production planning issues that lean on the introduction of NGVs from GM. The initial target is light and medium duty trucks sold in non-attainment air quality regions. GM has also embarked on a longer term program that encompasses vehicle and systems development, gas supply and infrastructure development, and customer and market development. The major long-term issues are gas quality, supplier participation, and infrastructure

Natural gas is more than gas power plants

International Nuclear Information System (INIS)

Lind, Oddvar

2000-01-01

Through the Statpipe gas line at Karmoey, Norway supplies 20% of the natural gas on the European market. The pipeline is 'leaking' a little bit of gas to the local communities at Karmoey and Haugesund. These communities have replaced 65% of their oil consumption with natural gas, which is a fine contribution to a better environment. The supplier of the natural gas, Gasnor ASA in this case, claims an energy efficiency of 90% at the end user because the gas burns directly and the loss in the pipeline is minimal. The efficiency of natural gas utilisation is twice that of the planned gas power stations in West-Norway, subtracting the losses in the electrical network. Gasnor ASA competes with oil suppliers and, if necessary, with electric utilities. The county hospital at Haugesund is quoted as an example. The hospital has two large boilers with dual fuel burners. They have been using natural gas since 1998 because it was worth while both economically and environmentally. The use of natural gas in the transport sector would be very important, but the necessary infrastructure is very little developed. For instance, five diesel-powered ferries on the Boknafjord emit as much NOx as the planned gas power plant at Kaarstoe

Experimental Study of Gas Explosions in Hydrogen Sulfide-Natural Gas-Air Mixtures

Directory of Open Access Journals (Sweden)

André Vagner Gaathaug

2014-01-01

Full Text Available An experimental study of turbulent combustion of hydrogen sulfide (H2S and natural gas was performed to provide reference data for verification of CFD codes and direct comparison. Hydrogen sulfide is present in most crude oil sources, and the explosion behaviour of pure H2S and mixtures with natural gas is important to address. The explosion behaviour was studied in a four-meter-long square pipe. The first two meters of the pipe had obstacles while the rest was smooth. Pressure transducers were used to measure the combustion in the pipe. The pure H2S gave slightly lower explosion pressure than pure natural gas for lean-to-stoichiometric mixtures. The rich H2S gave higher pressure than natural gas. Mixtures of H2S and natural gas were also studied and pressure spikes were observed when 5% and 10% H2S were added to natural gas and also when 5% and 10% natural gas were added to H2S. The addition of 5% H2S to natural gas resulted in higher pressure than pure H2S and pure natural gas. The 5% mixture gave much faster combustion than pure natural gas under fuel rich conditions.

Mechanical, thermo dynamical and environmental comparison of engines using natural gas and gasoline

International Nuclear Information System (INIS)

Agudelo S, John R; Bedoya C, Ivan D; Moreno S, Ricardo

2005-01-01

This paper shows experimental results of a Toyota Hilux 2400-swept volume, compression ratio 9:1 engine, operating with La Guajira natural gas and petrol. Also shows a thermodynamic study of those fuels in a normalized, variable compression ratio ASTM-CFR monocylinder engine. When using natural gas, Hilux engine increases its fuel consumption around 20% for the same power. Volumetric efficiency increases 10% and co emissions de- crease around 40%. When comparing thermodynamic parameters in CFR engine operating at a compression ratio of 9:1, it was found a 12,5% decrease in indicated power and 17% in maximum combustion pressure, which is proportional to temperature diminish of around 20%. Convective heat transfer coefficient decreases around 28% respect to petrol. First laminar combustion phase is duplicated when using the same spark advance as petrol; nevertheless this is maintained almost constant when spark is advancing 15 degrades over petrol spark advance

Constructing a unique two-phase compressibility factor model for lean gas condensates

Energy Technology Data Exchange (ETDEWEB)

Moayyedi, Mahmood; Gharesheikhlou, Aliashghar [Research Institute of Petroleum Industry (RIPI), Tehran (Iran, Islamic Republic of); Azamifard, Arash; Mosaferi, Emadoddin [Amirkabir University of Technology (AUT), Tehran (Iran, Islamic Republic of)

2015-02-15

Generating a reliable experimental model for two-phase compressibility factor in lean gas condensate reservoirs has always been demanding, but it was neglected due to lack of required experimental data. This study presents the main results of constructing the first two-phase compressibility factor model that is completely valid for Iranian lean gas condensate reservoirs. Based on a wide range of experimental data bank for Iranian lean gas condensate reservoirs, a unique two-phase compressibility factor model was generated using design of experiments (DOE) method and neural network technique (ANN). Using DOE, a swift cubic response surface model was generated for two-phase compressibility factor as a function of some selected fluid parameters for lean gas condensate fluids. The proposed DOE and ANN models were finally validated using four new independent data series. The results showed that there is a good agreement between experimental data and the proposed models. In the end, a detailed comparison was made between the results of proposed models.

Constructing a unique two-phase compressibility factor model for lean gas condensates

International Nuclear Information System (INIS)

Moayyedi, Mahmood; Gharesheikhlou, Aliashghar; Azamifard, Arash; Mosaferi, Emadoddin

2015-01-01

Generating a reliable experimental model for two-phase compressibility factor in lean gas condensate reservoirs has always been demanding, but it was neglected due to lack of required experimental data. This study presents the main results of constructing the first two-phase compressibility factor model that is completely valid for Iranian lean gas condensate reservoirs. Based on a wide range of experimental data bank for Iranian lean gas condensate reservoirs, a unique two-phase compressibility factor model was generated using design of experiments (DOE) method and neural network technique (ANN). Using DOE, a swift cubic response surface model was generated for two-phase compressibility factor as a function of some selected fluid parameters for lean gas condensate fluids. The proposed DOE and ANN models were finally validated using four new independent data series. The results showed that there is a good agreement between experimental data and the proposed models. In the end, a detailed comparison was made between the results of proposed models

Burning low volatile fuel in tangentially fired furnaces with fuel rich/lean burners

International Nuclear Information System (INIS)

Wei Xiaolin; Xu Tongmo; Hui Shien

2004-01-01

Pulverized coal combustion in tangentially fired furnaces with fuel rich/lean burners was investigated for three low volatile coals. The burners were operated under the conditions with varied value N d , which means the ratio of coal concentration of the fuel rich stream to that of the fuel lean stream. The wall temperature distributions in various positions were measured and analyzed. The carbon content in the char and NO x emission were detected under various conditions. The new burners with fuel rich/lean streams were utilized in a thermal power station to burn low volatile coal. The results show that the N d value has significant influences on the distributions of temperature and char burnout. There exists an optimal N d value under which the carbon content in the char and the NO x emission is relatively low. The coal ignition and NO x emission in the utilized power station are improved after retrofitting the burners

Incremental natural gas resources through infield reserve growth/secondary natural gas recovery

Energy Technology Data Exchange (ETDEWEB)

Finley, R.J.; Levey, R.A.; Hardage, B.A.

1993-12-31

The primary objective of the Infield Reserve Growth/Secondary Natural Gas Recovery (SGR) project is to develop, test, and verify technologies and methodologies with near- to midterm potential for maximizing the recovery of natural gasfrom conventional reservoirs in known fields. Additional technical and technology transfer objectives of the SGR project include: To establish how depositional and diagenetic heterogeneities in reservoirs of conventional permeability cause reservoir compartmentalization and, hence, incomplete recovery of natural gas. To document examples of reserve growth occurrence and potential from fluvial and deltaic sandstones of the Texas gulf coast basin as a natural laboratory for developing concepts and testing applications to find secondary gas. To demonstrate how the integration of geology, reservoir engineering, geophysics, and well log analysis/petrophysics leads to strategic recompletion and well placement opportunities for reserve growth in mature fields. To transfer project results to a wide array of natural gas producers, not just as field case studies, but as conceptual models of how heterogeneities determine natural gas flow units and how to recognize the geologic and engineering clues that operators can use in a cost-effective manner to identify incremental, or secondary, gas.

Emissão de mercúrio para a atmosfera pela queima de gás natural no Brasil Mercury emissions to the atmosphere from natural gas burning in Brazil

Directory of Open Access Journals (Sweden)

Luiz Drude de Lacerda

2007-04-01

Full Text Available Increasing natural gas use in Brazil triggered a discussion of its role as a Hg source. We show that Hg emissions to the atmosphere from fossil fuel combustion for power generation in Brazil contribute with 6.2% (4.2 t yr-1 to the total anthropogenic Hg atmospheric emissions, with coal combustion and biomass burning as major sources. Natural gas contributes with 0.04 t yr-1, mostly from electricity generation (88% and industrial uses (7.6%. Preliminary results on Hg concentrations in natural gas suggest that a large fraction of it is trapped during refining and transport, which may create Hg point sources between extraction and consumption.

Role of natural gas in meeting an electric sector emissions reduction strategy and effects on greenhouse gas emissions

Science.gov (United States)

With advances in natural gas extraction technologies, there is an increase in availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but unce...

Effect of hydrogen addition on burning rate and surface density of turbulent lean premixed methane-air flames

International Nuclear Information System (INIS)

Guo, H.; Tayebi, B.; Galizzi, C.; Escudie, D.

2009-01-01

Hydrogen (H 2 ) is a clean burning component, but relatively expensive. Mixing a small amount of hydrogen with other fuels is an effective way to use H 2 . H 2 enriched combustion significantly improves fuel efficiency and reduces pollutant (nitrogen oxide and particulate matter) emissions. This presentation discussed the effect of hydrogen addition on burning rate and surface density of turbulent lean premixed methane-air flames. The presentation discussed flame configuration; the experimental methodology using laser tomography; and results for typical images, burning velocity, ratio of turbulent to laminar burning velocities, flame surface density, curvature, flame brush thickness, and integrated flame surface area. It was concluded that the increase of turbulent burning velocity was faster than that of laminar burning velocity, which contradicted traditional theory. figs.

Future perspective for CNG (Compressed Natural Gas)

International Nuclear Information System (INIS)

Veen, D.

1999-01-01

Driving on natural gas (CNG, Compressed Natural Gas) has been the talk of the industry for many years now. Although the benefits of natural gas as an engine fuel have become well-known, this phenomenon does not seem to gain momentum in the Netherlands. Over the last few months, however, the attitude towards CNG seems to be changing. Energy companies are increasingly engaged in commercial activities, e.g. selling natural gas at petrol stations, an increasing number of car manufacturers are delivering natural gas vehicles ex-works, and recently the NGV (Natural Gas Vehicles) Holland platform was set up for the unequivocal marketing of natural gas as an engine fuel

Evaluation of Ultra Clean Fuels from Natural Gas

Energy Technology Data Exchange (ETDEWEB)

Robert Abbott; Edward Casey; Etop Esen; Douglas Smith; Bruce Burke; Binh Nguyen; Samuel Tam; Paul Worhach; Mahabubul Alam; Juhun Song; James Szybist; Ragini Acharya; Vince Zello; David Morris; Patrick Flynn; Stephen Kirby; Krishan Bhatia; Jeff Gonder; Yun Wang; Wenpeng Liu; Hua Meng; Subramani Velu; Jian-Ping Shen, Weidong Gu; Elise Bickford; Chunshan Song; Chao-Yang Wang; Andre' Boehman

2006-02-28

ConocoPhillips, in conjunction with Nexant Inc., Penn State University, and Cummins Engine Co., joined with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) in a cooperative agreement to perform a comprehensive study of new ultra clean fuels (UCFs) produced from remote sources of natural gas. The project study consists of three primary tasks: an environmental Life Cycle Assessment (LCA), a Market Study, and a series of Engine Tests to evaluate the potential markets for Ultra Clean Fuels. The overall objective of DOE's Ultra Clean Transportation Fuels Initiative is to develop and deploy technologies that will produce ultra-clean burning transportation fuels for the 21st century from both petroleum and non-petroleum resources. These fuels will: (1) Enable vehicles to comply with future emission requirements; (2) Be compatible with the existing liquid fuels infrastructure; (3) Enable vehicle efficiencies to be significantly increased, with concomitantly reduced CO{sub 2} emissions; (4) Be obtainable from a fossil resource, alone or in combination with other hydrocarbon materials such as refinery wastes, municipal wastes, biomass, and coal; and (5) Be competitive with current petroleum fuels. The objectives of the ConocoPhillips Ultra Clean Fuels Project are to perform a comprehensive life cycle analysis and to conduct a market study on ultra clean fuels of commercial interest produced from natural gas, and, in addition, perform engine tests for Fisher-Tropsch diesel and methanol in neat, blended or special formulations to obtain data on emissions. This resulting data will be used to optimize fuel compositions and engine operation in order to minimize the release of atmospheric pollutants resulting from the fuel combustion. Development and testing of both direct and indirect methanol fuel cells was to be conducted and the optimum properties of a suitable fuel-grade methanol was to be defined. The results of the study are also

Survey on the reduction technology of greenhouse effect gas emission from automobiles; Jidosha kara no onshitsu koka gas haishutsuryo teigen gijutsu no chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The developmental trend of the reduction technology of greenhouse effect gas emission from automobiles was surveyed. Development of low pollution, energy saving and substituting energy vehicles such as electric, methanol and natural gas vehicles is in rapid progress together with performance improvement of conventional gasoline vehicles. For example, since GDI engine directly injects fuel into cylinders, it can control an air/fuel ratio at will, and reduce CO2 emission. Lean burn engine vehicle and hybrid vehicle are also under development. Performance improvement of storage batteries for electric vehicles, in particular, that combined with solar cells, and the practicability of hybrid vehicles are being clarified. Among them, the superiority of fuel cell technology in the future is becoming clear from a general viewpoint, because of its high efficiency and no CO2 emission. As methanol is produced from plants, construction of cyclic energy systems is promising. However, since low emission vehicles are expensive, some policies such as legal obligation and subsidy system are important. 30 refs., 95 figs., 26 tabs.

New engineers for the natural gas and petroleum industry; Nachwuchs fuer die Erdgas-/Erdoelindustrie

Energy Technology Data Exchange (ETDEWEB)

Reinicke, K.M.; Pusch, G. [TU Clausthal (Germany). Inst. fuer Erdoel- und Erdgastechnik

2007-09-13

Tne natural gas and petroleum industry needs engineers. Universities are faced with the challenge of training them and ensuring their technical, communicative and personal skills. Universities are taking new strategies to do this, joining efforts with other universities and with the oil and natural gas industry. New media are employed, increasingly also for advanced training and for learning by correspondence course in order to provide students with special knowledge and facilitate career changes. The paper describes implemented and projected studies in petroleum and natural gas technology at TU Clausthal university and joint projects with partner universities and industry. (orig.)

Carbon Nanostructure of Diesel Soot Particles Emitted from 2 and 4 Stroke Marine Engines Burning Different Fuels.

Science.gov (United States)

Lee, Won-Ju; Park, Seul-Hyun; Jang, Se-Hyun; Kim, Hwajin; Choi, Sung Kuk; Cho, Kwon-Hae; Cho, Ik-Soon; Lee, Sang-Min; Choi, Jae-Hyuk

2018-03-01

Diesel soot particles were sampled from 2-stroke and 4-stroke engines that burned two different fuels (Bunker A and C, respectively), and the effects of the engine and fuel types on the structural characteristics of the soot particle were analyzed. The carbon nanostructures of the sampled particles were characterized using various techniques. The results showed that the soot sample collected from the 4-stroke engine, which burned Bunker C, has a higher degree of order of the carbon nanostructure than the sample collected from the 2-stroke engine, which burned Bunker A. Furthermore, the difference in the exhaust gas temperatures originating from the different engine and fuel types can affect the nanostructure of the soot emitted from marine diesel engines.

A study of burning processes of fossil fuels in straitened conditions of furnaces in low capacity boilers by an example of natural gas

Science.gov (United States)

Roslyakov, P. V.; Proskurin, Y. V.; Khokhlov, D. A.; Zaichenko, M. N.

2018-03-01

The aim of this work is to research operations of modern combined low-emission swirl burner with a capacity of 2.2 MW for fire-tube boiler type KV-GM-2.0, to ensure the effective burning of natural gas, crude oil and diesel fuel. For this purpose, a computer model of the burner and furnace chamber has been developed. The paper presents the results of numerical investigations of the burner operation, using the example of natural gas in a working load range from 40 to 100%. The basic features of processes of fuel burning in the cramped conditions of the flame tube have been identified to fundamentally differ from similar processes in the furnaces of steam boilers. The influence of the design of burners and their operating modes on incomplete combustion of fuel and the formation of nitrogen oxides has been determined.

Development and validation of a quasi-dimensional combustion model for SI engines fuelled by HCNG with variable hydrogen fractions

Energy Technology Data Exchange (ETDEWEB)

Ma, Fanhua; Wang, Yu; Wang, Mingyue; Liu, Haiquan; Wang, Junjun; Ding, Shangfen; Zhao, Shuli [State Key Laboratory of Automobile Safety and Energy, Tsinghua University, Beijing 100084 (China)

2008-09-15

Spark ignition engines fuelled by hydrogen enriched compressed natural gas (HCNG) have many advantages compared to traditional gasoline, diesel and natural gas engines, especially in emission control. Experimental researches have been continuously conducted to improve HCNG engine's configuration and control strategy aimed at making full use of this new fuel. With the same target, this work presents a predictive model used to simulate the working cycle of HCNG engines which is applicable for variable hydrogen blending ratios. The fundamentals of the thermodynamic model, the turbulent flame propagation model and related equation were introduced. Considering that the most important factor influencing the applicability of the model for variable hydrogen blending ratio is the laminar flame speed, the methods of how to deal with the laminar burning velocity in the model were then described in some more detail. After the determination of model constants by calibration, simulation results were compared with experimental cylinder pressure data for various hydrogen blending ratios, spark timings and equivalence ratios. The results show that simulation and experimental results match quite well except for extremely fuel lean conditions where problems of incomplete combustion become severe. (author)

Optimization of large bore gas engine

International Nuclear Information System (INIS)

Laiminger, S.

1999-01-01

This doctoral thesis is concerned with the experimental part of combustion optimization of a large bore gas engine. Nevertheless there was a very close co-operation with the simultaneous numeric simulation. The terms of reference were a systematic investigation of the optimization potential of the current combustion mode with the objective target to get a higher brake efficiency and lower NO x emissions. In a second part a new combustion mode for fuels containing H 2 , for fuels with very low heating value and for special fuels should be developed. The optimization contained all relevant components of the engine to achieve a stable and well suited combustion with short duration even with very lean mixture. After the optimization the engine was running stable with substantial lower NO x emissions. It was world-wide the first time when a gas medium-sized engine could reach a total electrical efficiency of more than 40 percent. Finally a combustion mode for gaseous fuels containing H 2 was developed. The engine is running now with direct ignition and with prechamber ignition. Both modes reach approximately the same efficiency and thermodynamic stability. (author)

Gas fireplace contact burns in young children.

Science.gov (United States)

Zettel, Julie C; Khambalia, Amina; Barden, Wendy; Murthy, Trisha; Macarthur, Colin

2004-01-01

Contact burns from domestic appliances are common in young children. Recently, gas fireplaces have been recognized as a potential cause of contact burns in young children. We sought to quantify the frequency of gas fireplace contact burns in young children, to identify the etiology of contact, to describe the clinical presentation, and to describe clinical outcomes. Children with gas fireplace contact burn injuries presenting to The Hospital for Sick Children in Toronto (1999-2002) were identified using three data sources: the Canadian Hospitals Injury Reporting and Prevention Program Database, the Burn Unit Registry, and the Rehabilitation Services Database. Demographic, clinical, and outcomes data were collected on all children. During the 4-year study period, 27 children presented to the hospital because of a gas fireplace contact burn (approximately 9% of all contact burns). The median age of the children was 14 months (range, 8-36 months), with 16 boys (59%). Most children were burned in their own home. With regard to etiology, 10 children (37%) lost their balance near the fireplace, 2 (7%) walked too close to the glass front, and 8 (30%) touched the glass front out of curiosity. Almost half (44%) of the children burned the palms and digits of both hands. The median total burn surface area was 1% (range, 0.2-2.5%). In total, 30% of children were admitted to hospital, and 11% required skin grafts. All children had full wound closure after 4 to 43 days. Given the etiology of these burns (loss of balance or curiosity), passive prevention, such as barriers or changes in the composition of glass panels, may be the most effective approach to combat them.

Liquefied natural gas storage at Ambergate

Energy Technology Data Exchange (ETDEWEB)

Higton, C W; Mills, M J

1970-08-19

Ambergate works was planned in 1965-1966 and the decision was taken to install 4 ICI lean gas reformers using natural gas as feedstock, fuel, and enrichment. To cover the possible failure of natural gas supplies, petroleum distillate would be used as alternative feedstock and fuel. The choice for alternative enrichment lay between LPG or LNG. Since LNG would provide peak-on-peak storage facilities for either the East Midlands Board or the Gas Council when conversion was completed--and in the meantime would provide an additional source of LNG for local requirements when temporary LNG installations were used during conversion--agreement was reached with the Gas Council for it to build a 5,000-ton storage installation at Ambergate. The installation consists of 3 major sections: (1) the offloading bay and storage tank; (2) the reliquefaction system; and (3) the export system. The offloading bay and storage tank are for the reception and storage of liquefied Algerian natural gas, delivered to Ambergate by road tanker from the Canvey Is. Terminal. The reliquefaction system is to maintain the necessary storage tank conditions by reliquefying the boil-off natural gas. The export system delivers LNG from the storage tank at high pressure through a vaporization section in the national methane grid.

Experimental and modelling study of reverse flow catalytic converters for natural gas/diesel dual fuel engine pollution control

Energy Technology Data Exchange (ETDEWEB)

Liu, B.

2000-07-01

There is renewed interest in the development of natural gas vehicles in response to the challenge to reduce urban air pollution and consumption of petroleum. The natural gas/diesel dual fuel engine is one way to apply natural gas to the conventional diesel engine. Dual fuel engines operating on natural gas and diesel emit less nitrogen oxides, and less carbon soot to the air compared to conventional diesel engines. The problem is that at light loads, fuel efficiency is reduced and emissions of hydrocarbons and carbon monoxide are increased. This thesis focused on control methods for emissions of hydrocarbons and carbon monoxide in the dual fuel engine at light loads. This was done by developing a reverse flow catalytic converter to complement dual fuel engine exhaust characteristics. Experimental measurements and numerical simulations of reverse flow catalytic converters were conducted. Reverse flow creates a high reactor temperature even when the engine is run at low exhaust temperature levels at light loads. The increase in reactor temperature from reverse flow could be 2 or 3 times higher than the adiabatic temperature increase, which is based on the reactor inlet temperature and concentration. This temperature makes it possible for greater than 90 per cent of the hydrocarbon and carbon monoxide to be converted with a palladium based catalyst. Reverse flow appears to be better than conventional unidirectional flow to deal with natural gas/diesel dual fuel engine pollution at light loads. Reverse flow could also maintain reactor temperature at over 800 K and hydrocarbon conversion at about 80 per cent during testing. The newly presented model simulates reactor performance with reasonable accuracy. Both carbon monoxide and methane oxidation over the palladium catalyst in excess oxygen and water were described using first order kinetics.

A Second Generation Swirl-Venturi Lean Direct Injection Combustion Concept

Science.gov (United States)

Tacina, Kathleen M.; Chang, Clarence T.; He, Zhuohui Joe; Lee, Phil; Dam, Bidhan; Mongia, Hukam

2014-01-01

A low-NO (sub x) aircraft gas turbine engine combustion concept was developed and tested. The concept is a second generation swirl-venturi lean direct injection (SV-LDI) concept. LDI is a lean-burn combustion concept in which the fuel is injected directly into the flame zone. Three second generation SV-LDI configurations were developed. All three were based on the baseline 9-point SV-LDI configuration reported previously. These second generation configurations had better low power operability than the baseline 9-point configuration. Two of these second generation configurations were tested in a NASA Glenn Research Center flametube; these two configurations are called the at dome and 5-recess configurations. Results show that the 5-recess configuration generally had lower NO (sub x) emissions than the flat dome configuration. Correlation equations were developed for the flat dome configuration so that the landing-takeoff NO (sub x) emissions could be estimated. The flat dome landing-takeoff NO (sub x) is estimated to be 87-88 percent below the CAEP/6 standards, exceeding the ERA project goal of 75 percent reduction.

Performance of an Otto cycle motor with natural gas direct injection; Desempenho de um motor ciclo Otto com injecao direta de gas natural

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Cleiton Rubens Formiga

1997-07-01

A Otto cycle engine with natural gas direct injection, during the inlet stroke, was submitted to runs with full power in a Foucaut dynamometer. The results obtained show a increase in the volumetric efficiency of the engine with natural gas direct injection when compared with natural gas injection applied in the inlet manifold, upstream of the throttle butterfly. In the conversion to natural gas direct injection, the technical characteristics were not changed. A kit for natural gas direct injection, with electronic management was located on the cylinder head of the test engine. Maintaining the pressure constant in the natural gas fuel line, using a reduction valve, the mass of fuel injected into the cylinder was regulated, varying the opening time of the solenoid valve fuel injector. Engine performance data is compared, emphasizing the factors that contribute to this increase in relative volumetric efficiency. Modifications are made to maximize the power of the engine with natural gas direct injection. (author)

Designing Workshops for the Introduction of Lean Enablers to Engineering Programs

DEFF Research Database (Denmark)

Gersing, Kilian; Oehmen, Josef; Rebentisch, Eric Rebentisch

2014-01-01

There is a large and growing body of knowledge regarding so-called Lean best practices, including most recently in the area of program management and systems engineering. However, there is little elaboration of how these documented best practices are to be introduced to a professional workforce. ...... the Lean principles. The framework was validated through interactions with training professionals in a large automobile manufacturer, and using subject matter experts from a variety of industrial sectors. © 2014 The Authors. Published by Elsevier B.V.......There is a large and growing body of knowledge regarding so-called Lean best practices, including most recently in the area of program management and systems engineering. However, there is little elaboration of how these documented best practices are to be introduced to a professional workforce...... the systematic design of workshops focused specifically on the introduction of Lean principles and practices to program management and the professional workforce in a program environment. The framework is based on a thorough review of literature on training, workshop delivery, and Lean principles, as well...

Experimental study of the effects of natural gas injection timing on the combustion performance and emissions of a turbocharged common rail dual-fuel engine

International Nuclear Information System (INIS)

Yang, Bo; Wei, Xing; Xi, Chengxun; Liu, Yifu; Zeng, Ke; Lai, Ming-Chia

2014-01-01

Highlights: • Natural gas injection timing has obvious effects on combustion of dual-fuel engine. • Combustion performance is improved with optimized natural gas injection timing. • BSHC and BSCO decreased with retarded natural gas injection timing at low load. • BSNO x increased at part load while reduced at high load with delay N.G. injection. • PM is very low and insensitive to the variation of natural gas injection timing. - Abstract: Natural gas combustion with pilot ignition has been considered to be one of the most promising ways to utilize natural gas in existing diesel engine without serious engine modification and it has been widely researched all over the world. In this study, three experiments of different loads (BMEP 0.240 MPa, 0.480 MPa and 0.767 MPa) were performed on a 2.8 L four-cylinder, natural gas manifold injection dual-fuel engine to investigate the effects of natural gas injection timing on engine combustion performance and emissions. The pilot injection parameters (pilot injection timing and pressure) and natural gas injection pressure remain constant at a speed of 1600 rpm in the experiment. The cylinder pressure, HRR, CoV imep , flame development duration, CA50 and brake thermal efficiency were analyzed. The results indicated that under low and part engine loads, the flame development duration and CA50 can be reduced by properly retarding natural gas injection timing, while the CoV imep increased with retarded natural gas injection timing. As a result, the brake thermal efficiency is increased and the combustion stability slightly deteriorates. Meanwhile, under low and part engine loads, PM emissions in the dual-fuel engine is much lower than that in conventional diesel engines, furthermore, at high load, the PM emissions are near zero. CO and HC emissions are reduced with retarded natural gas injection timing under low and part loads, however, NO x emissions are slightly increased. Under high load, the flame development duration

Virtual modelling of components of a production system as the tool of lean engineering

Science.gov (United States)

Monica, Z.

2015-11-01

Between the most effective techniques of manufacturing management is considered the Lean Engineering. The term “lean engineering” was created by Japanese manufacturers. The high efficiency of this method resulted in a meaningful growth in concern in the philosophy of Lean among European companies, and consequently the use of its European markets. Lean philosophy is an approach to manufacturing to minimize the use of all resources, including time. These are resources that are used in the company for a variety of activities. This implies, first identify and then eliminate activities which does not generate added value in the field of design, manufacturing, supply chain management, and customer relations. The producers of these principles not only employ teams multi-professional employees at all levels of the organization, but also use a more automated machines to produce large quantities of products with a high degree of diversity. Lean Engineering is to use a number of principles and practical guidelines that allow you to reduce costs by eliminating absolute extravagance, and also simplification of all manufacturing processes and maintenance. Nowadays it could be applied the powerful engineering programs to realize the concept of Lean Engineering. They could be described using the term CAD/CAM/CAE. They consist of completely different packages for both the design of elements, as well process design. Their common feature is generally considered with their application area. They are used for computer programs assisting the design, development and manufacturing phases of a manufacturing process. The idea of the presented work is to use the Siemens NX software for aiding the process of Lean Engineering system creating. The investigated system is a robotized workcell. In the NX system are created the components of the designed workcell such as machine tools, as industrial robot, as conveyors and buffers. The system let to functionally link these components to

EDUCATION FOR LEAN & LEAN FOR EDUCATION: A LITERATURE REVIEW

Directory of Open Access Journals (Sweden)

Saveta Vukadinovic

2017-03-01

Full Text Available The purpose of this paper is to investigate and understand how tools and principles of Lean philosophy can be adopted to improve the effectiveness of engineering education by providing services beyond the competition and costs below the competition, and how engineering education can provide better prepared engineering professionals capable to work in dynamic Lean environments by developing multidisciplinary knowledge and skills. Paper will be based on analysis of relevant scientific and professional literature sources, including certain elements of description, classification, explanation and prediction. The authors will use detailed literature review to explain complex relationship and interdependence between Lean philosophy and engineering education and answer the question what benefits modern Lean enterprises may expect from properly educated and qualified engineers and how application of Lean tools and principles can improve the system of engineering education.

Review of modern low emissions combustion technologies for aero gas turbine engines

Science.gov (United States)

Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Nalianda, Devaiah; Li, Yi-Guang; Wang, Lu

2017-10-01

Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of the review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.

Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

Science.gov (United States)

Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

2008-11-25

A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

Diesel and gas engines: evolution following new regulations; Moteurs diesel et gaz: evolution face aux nouvelles reglementations

Energy Technology Data Exchange (ETDEWEB)

Deverat, Ph. [Bergerat Monnoyeur (France). Direction Industrie

1997-12-31

Engine emissions of CO, NMHC and ashes are easily lowered through a low-cost exhaust gas processing, while NOx processing in fumes is rather complex and environmentally hazardous; thus, engine manufacturers have emphasized their researches for NOx decrease on the engine design: lower combustion temperature in diesel engines through water cooling or air/air exchanger, lean mixture with excess air (open chamber or pre-chamber) in spark ignition gas engines. Examples of modifications in Caterpillar engines are given. Exhaust gas processing for CO, NMHC, NOx (3 way catalytic purifier, selective catalytic reduction) and ashes is also discussed

Desempeño y emisiones de un motor de combustión interna con combustible dual Diesel – Gas natural ;Performance and emissions study of an internal combustion engine with dual fuel diesel - natural gas

Directory of Open Access Journals (Sweden)

Juan Miguel Mantilla González

2015-04-01

Full Text Available Muchos de los problemas reportados para los sistemas duales diesel- gas natural ocurren por mala dosificación del gas. Por esta razón se adaptó un sistema de alimentación dual con inyección electrónica de gas natural a un motor de combustión interna encendido por compresión. Se plantea un diseño experimental controlando el dosado de gas natural.Como resultado se obtiene un análisis comparativo entre los valoresde desempeño y emisiones desde la operación Diesel y Diesel-Gas natural. A partir de este análisis es posible observar que el desempeño del motor no se ve afectado por la operación del motor bajo el esquema Dual Diesel-GN, es decir que el motor funcionando bajo modo dual puede sostener las cargas solicitadas al motor. También se observa que la eficiencia volumétrica mejora bajo todas las condiciones de operación dual y las emisiones son mejores sólo cuando el motor trabaja a altas cargas. Many of the problems reported for dual diesel-natural gas systems occur due to poor gas dosage. For this reason a natural gas electronic injection feeding system was adapted to a compression ignitios internal combustion engine. An experimental design controlling the natural gas dosage is considered. As a result a comparative analysis between performance and emissions from the Diesel-and diesel-Natural Gas operation is obtained. From this analysis it is possible to see that engine performance is not affected by operation of the engine under the dual mode, i.e. the motor running under dual mode can support the loads applied to the engine. It is also observed that the volumetric efficiency improves under all conditions of operation and emissions from the dual mode of operation are better only when working at high engine loads.

Penetration of natural gas in industrial processes for direct burning: the case of ceramics, cement and glass industries; Penetracao do gas natural em processos industriais de queima direta: caso das industrias ceramica, cimento e vidro

Energy Technology Data Exchange (ETDEWEB)

Berni, Mauro Donizeti; Leite, Alvaro A. Furtado [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Dorileo, Ivo Leandro [Universidade Federal do Mato Grosso (NIEPE/UFMT), Cuiaba, MT (Brazil). Nucleo Interdisciplinar de Estudos em Planejamento Energetico; Bajay, Sergio Valdir [Universidade estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Energia], e-mail: bajay@fem.unicamp.com.br

2008-07-01

Industrial sector can use the natural gas (NG) as raw material, as fuel and in co-generation. The NG as fuel is used, predominantly, to produce heat in the Brazilian industries. That rate, both main forms of industrial use of the NG are its direct burning in kilns - when the direct contact is had with the product - and the supply of process heat through boilers, for instance. Direct burning is used in the ceramic, cement and glass industries. This work discuss the penetration opportunity of the NG in the direct burning regarding the fuel oil and other energy that it can substitute, the environmental effects and the co-generation possibilities in each one of the analyzed industrial blanches in this work. (author)

Natural gas : a highly lucrative commodity

International Nuclear Information System (INIS)

Anon.

2000-01-01

Exploration and production of natural gas has become highly profitable as natural gas is becoming a leading future commodity. With new technology, high demand and environmental benefits, natural gas is the preferred choice over petroleum as the leading source of energy to heat home and businesses. Canada is the world's third largest producer of natural gas with its Sable Offshore Energy Project being the fourth largest producing natural gas basin in North America. The basin will produce high quality sweet natural gas from 28 production wells over the course of the next 20 to 25 years. The gas will be transported to markets through Nova Scotia, New Brunswick and into the Northeastern United States via the Maritimes and Northeast Pipeline. The 1051 kilometer underground gas pipeline is currently running laterals to Halifax, Nova Scotia and Saint John, New Brunswick. Market studies are being conducted to determine if additional lines are needed to serve Cape Breton, Prince Edward Island and northern New Brunswick. A recent survey identified the following 5 reasons to convert to natural gas: (1) it is safe, (2) it is reliable, (3) it is easy to use, (4) it is cleaner burning and environmentally friendly compared to other energy sources, and (5) it saves the consumer money

Ecobalance of natural gas vehicles; Oekobilanz von Erdgasfahrzeugen

Energy Technology Data Exchange (ETDEWEB)

Nigge, K.M. [Simon, Kucher und Partners Strategy und Marketing Consultants GmbH, Bonn (Germany)

2000-07-01

The impacts on human health and the natural environment of using natural gas, Diesel and petrol as fuels for city buses and passenger cars are compared in a Life Cycle Assessment. In addition to the burning of the fuels in the engines, this assessment also comprises the upstream processes of the fuel supply chain. Despite the increased energy demand of the vehicles, natural gas is associated with the lowest impacts overall for both city buses and passenger cars. The health impacts that can be avoided through the use of natural gas instead of Diesel or petrol thereby differ only weakly between the use of the vehicles in cities of various sizes within Germany. From the perspective of environmental protection, the market introduction of natural gas vehicles therefore does not need remain limited to large cities within agglomerated regions. (orig.) [German] Die Auswirkungen der Verwendung von Erdgas, Diesel und Benzin als Kraftstoffe fuer Stadtbusse und Pkw auf die menschliche Gesundheit und die natuerliche Umwelt werden in einer Oekobilanz verglichen. Diese umfasst neben der motorischen Verbrennung der Kraftstoffe auch die vorgelagerten Prozessketten der Kraftstoffbereitstellung. Sowohl fuer Stadtbusse als auch fuer Pkw schneidet Erdgas trotz eines energetischen Mehrbedarfes der Fahrzeuge insgesamt am guenstigsten ab. Die durch den Einsatz von Erdgas anstelle von Diesel oder Benzin vermeidbaren Gesundheitsschaeden unterscheiden sich dabei zwischen einem Einsatz der Fahrzeuge in Staedten verschiedener Groesse innerhalb von Deutschland nur wenig. Die Markteinfuehrung von Erdgasfahrzeugen muss also aus Sicht des Umweltschutzes nicht auf grosse Staedte in Ballungsgebieten beschraenkt bleiben. (orig.)

Effect of Diesel Engine Converted to Sequential Port Injection Compressed Natural Gas Engine on the Cylinder Pressure vs Crank Angle in Variation Engine Speeds

OpenAIRE

Semin; Abdul R. Ismail; Rosli A. Bakar

2009-01-01

The diesel engine converted to compressed natural gas (CNG) engine effect is lower in performance. Problem statement: The hypothesis is that the lower performance of CNG engine is caused by the effect of lower in engine cylinder pressure. Are the CNG engine is lower cylinder pressure than diesel engine? This research is conducted to investigate the cylinder pressure of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: The research approach in this study is b...

Implementation of NOx emissions standard in the Gas Transmission Company in the Netherlands

International Nuclear Information System (INIS)

Veenstra, T.; Coors, P.; Rosmalen, R.J.

1992-01-01

In 1987 and 1990 new NO x emission standards came in force for firing installations (boilers, gas turbines and engines). Gasunie (the gas transportation company in The Netherlands) owns 55 gas turbines and 10 gas engines for the gastransport system, with a total capacity of about 570 MW, installed in 8 compressor stations. Having the most stringent emission levels of Europe (together with Germany) Gasunie reduced the total NO x amount from 3600 tons of NO x in 1987 to 630 tons of NO x in 1990. This reduction was mostly based on our own development of a new precombustion chamber for the lean burn gas engines. Besides that studies and research were carried out for NO x reduction on the gas turbine to meet the current legislation (115 ppm NO x ) and a strategy is made to meet future emission standards. This is necessary because the expected future NO x standards for stand alone gas turbines will be about half of the present standards

Numerical investigation on the effects of natural gas and hydrogen blends on engine combustion

Energy Technology Data Exchange (ETDEWEB)

Morrone, Biagio; Unich, Andrea [Dipartimento di Ingegneria Aerospaziale e Meccanica (DIAM), Seconda Universita degli Studi di Napoli via Roma 29, 81031 Aversa (CE) (Italy)

2009-05-15

The use of hydrogen blended with natural gas is a viable alternative to pure fossil fuels because of the expected reduction of the total pollutant emissions and increase of efficiency. These blends offer a valid opportunity for tackling sustainable transportation, in view of the future stringent emission limits for road vehicles. The aim of the present paper is the investigation of the performance of internal combustion engines fuelled by such blends. A numerical investigation on the characteristics of natural gas-hydrogen blends as well as their effect on engine performance is carried out. The activity is focused on the influence of such blends on flame propagation speed. Combustion pattern modelling allows the comparison of engine brake efficiency and power output using different fuels. Results showed that there is an increase in engine efficiency only if Maximum Brake Torque (MBT) spark advance is used for each fuel. Moreover, an economic analysis has been carried out to determine the over cost of hydrogen in such blends, showing percent increments by using these fuels about between 10 and 34%. (author)

Implementing lean in Malaysian universities: Lean awareness level in an engineering faculty of a local university

Science.gov (United States)

Azim Khairi, M.; Rahman, Mohamed Abd

2018-01-01

Many academic articles were published in Malaysia promoting the goodness of lean in manufacturing and industrial sectors but less attention was apparently given to the possibility of obtaining the same universal benefits when applying lean in non-manufacturing sectors especially higher education. This study aims to determine the level of lean awareness among a local university’s community taking its Faculty of Engineering (FoE) as the case study. It also seeks to identify typical FoE’s staff perception on lean regarding its benefits and the obstacles in implementing it. A web-based survey using questionnaires was carried out for 215 respondents consisting of academic and administrative staff of the faculty. Statistical Package for the Social Science (SPSS) was used to analyze the survey data collected. A total of 13.95% of respondents returned the forms. Slightly more than half of those responded (56.7%) have encountered some of the lean terms with mean 1.43 and standard deviation 0.504. However, the large amount of standard deviation somewhat indicates that the real level of lean awareness of FoE as a group was low. In terms of lean benefits, reduction of waste was favored (93.3%) by the respondents with mean 0.93 and standard deviation 0.254. For obstacles in implementing lean, lack of knowledge was selected by most respondents (86.7%) to be the major factor with mean 0.87 and standard deviation 0.346. Through the analysis done, the study may conclude that level of lean awareness among the university‘s community was low thus may hinder implementation of lean concept.

40 CFR 1065.715 - Natural gas.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Natural gas. 1065.715 Section 1065.715... PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.715 Natural gas. (a) Except as specified in paragraph (b) of this section, natural gas for testing must meet the...

Diluted Operation of a Heavy-Duty Natural Gas Engine - Aiming at Improved Effciency, Emission and Maximum Load

OpenAIRE

Kaiadi, Mehrzad

2011-01-01

Most heavy-duty engines are diesel operated. Severe emission regulations, high fuel prices, high technology costs (e.g. catalysts, fuel injection systems) and unsustainably in supplying fuel are enough reasons to convenience engine developers to explore alternative technologies or fuels. Using natural gas/biogas can be a very good alternative due to the attractive fuel properties regarding emission reduction and engine operation. Heavy-duty diesel engines can be easily converted for natur...

Natural gas cooling: Part of the solution

International Nuclear Information System (INIS)

Jones, D.R.

1992-01-01

This paper reviews and compares the efficiencies and performance of a number of gas cooling systems with a comparable electric cooling system. The results show that gas cooling systems compare favorably with the electric equivalents, offering a new dimension to air conditioning and refrigeration systems. The paper goes on to compare the air quality benefits of natural gas to coal or oil-burning fuel systems which are used to generate the electricity for the electric cooling systems. Finally, the paper discusses the regulatory bias that the author feels exists towards the use of natural gas and the need for modification in the existing regulations to provide a 'level-playing field' for the gas cooling industry

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES

Energy Technology Data Exchange (ETDEWEB)

Victor Wong; Tian Tian; Luke Moughon; Rosalind Takata; Jeffrey Jocsak

2006-03-31

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis is being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston and piston-ring dynamic and friction models have been developed and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukesha VGF 18GL engine confirmed total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. This represents a substantial (30-40%) reduction of the ringpack friction alone. The measured FMEP reductions were in good agreement with the model predictions. Further improvements via piston, lubricant, and surface designs offer additional opportunities. Tests of low-friction lubricants are in progress and preliminary results are very promising. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Piston friction studies indicate that a flatter piston with a more flexible skirt, together with optimizing the waviness and film thickness on the piston skirt offer significant friction reduction. Combined with low-friction ring-pack, material and lubricant parameters, a total power cylinder friction

Industry see in the natural gas use the solution for the energy crisis

International Nuclear Information System (INIS)

Sampaio, P.M.; Aristarcho, M.; Costa, D.B. da.

1991-01-01

Economical and political aspects of natural gas use in Brazil are described, mentioning the little use; the necessity due to collapse with supply of electric power, the foundation of INFRAGAS with the natural gas privatization; the self-sufficiency; the brazilian reserves and the reduction in natural gas burn. (author)

The new generation of exhaust aftertreatment systems for lean fuel gasoline engines; Die neue Generation von Abgasnachbehandlungssystemen fuer magerlaufende Benzinmotoren

Energy Technology Data Exchange (ETDEWEB)

Eckhoff, Stephan; Hoyer, Ruediger; Adam, Frank; Lammarck, Christian; Mueller, Wilfried [Umicore AG und Co. KG, Hanau-Wolfgang (Germany)

2010-07-01

Stratified gasoline direct injection engines show a great potential for the reduction of CO{sub 2} emissions and therefore improved fuel economy. The next generation of stratified gasoline engines with turbo charger and more efficient combustion are expected to have even lower exhaust temperatures compared with current series vehicle with stratified combustion. For this reason exhaust gas aftertreatment systems are required which have low light off temperatures for HC and CO during lean combustion and a high NOx-storage efficiency at low temperatures. This study shows the great improvements made over the last years for the development of new TWC and NOx-storage catalysts for the aftertreatment for lean GDI. A precious metal related cost reduction of about 40% was achieved for the new generation of aftertreatment systems. (orig.)

Assessment of future natural gas vehicle concepts

Science.gov (United States)

Groten, B.; Arrigotti, S.

1992-10-01

The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

Dedicated natural gas vehicle with low emission

NARCIS (Netherlands)

Voogd, A. de; Weide, J. van der; Konig, A.; Wegener, R.

1995-01-01

In the introduction an overview is given of international activities in the field of natural gas vehicles. The main incentives for the use of natural gas in vehicles are: emission reduction in urban areas, fuel diversification, and long term availability. Heavy duty natural gas engines are mainly

U.S. natural gas pipeline flow and demand trends

International Nuclear Information System (INIS)

Carson, M.M.

1992-01-01

It is no surprise that regional natural gas supply and demand patterns in North America are constantly changing. A consensus of forecasters agree that the natural gas resource base is larger than envisaged in the early 1980s due to advances in exploration and production technology. In addition, on the demand side more gas will be burned by US power generators to meet growth in electricity. Gas consumption is up in the commercial sector, and natural gas is correctly seen as environmentally protective. But how much more natural gas does the US need? This paper reports that new pipeline projects are springing up all over the nation --- 43 to be exact, with most of them connecting gas deliverability out of basins west of the Mississippi to new markets along the Atlantic and Pacific coasts

PIV Measurements of Gas Flow Fields from Burning End

Science.gov (United States)

Huang, Yifei; Wu, Junzhang; Zeng, Jingsong; Tang, Darong; Du, Liang

2017-12-01

To study the influence of cigarette gas on the environment, it is necessary to know the cigarette gas flow fields from burning end. By using PIV technique, in order to reveal velocity characteristics of gas flow fields, the velocities of cigarette gas flow fields was analyzed with different stepping motor frequencies corresponding to suction pressures, and the trend of velocity has been given with image fitting. The results shows that the velocities of the burning end increased with suction pressures; Between velocities of the burning end and suction pressures, the relations present polynomial rule; The cigarette gas diffusion in combustion process is faster than in the smoldering process.

The Tracer Gas Method of Determining the Charging Efficiency of Two-stroke-cycle Diesel Engines

Science.gov (United States)

Schweitzer, P H; Deluca, Frank, Jr

1942-01-01

A convenient method has been developed for determining the scavenging efficiency or the charging efficiency of two-stroke-cycle engines. The method consists of introducing a suitable tracer gas into the inlet air of the running engine and measuring chemically its concentration both in the inlet and exhaust gas. Monomethylamine CH(sub 3)NH(sub 2) was found suitable for the purpose as it burns almost completely during combustion, whereas the "short-circuited" portion does not burn at all and can be determined quantitatively in the exhaust. The method was tested both on four-stroke and on two-stroke engines and is considered accurate within 1 percent.

Essentials of natural gas microturbines

CERN Document Server

Boicea, Valentin A

2013-01-01

Addressing a field which, until now, has not been sufficiently investigated, Essentials of Natural Gas Microturbines thoroughly examines several natural gas microturbine technologies suitable not only for distributed generation but also for the automotive industry. An invaluable resource for power systems, electrical, and computer science engineers as well as operations researchers, microturbine operators, policy makers, and other industry professionals, the book: Explains the importance of natural gas microturbines and their use in distributed energy resource (DER) systemsDiscusses the histor

Canadian natural gas and climate change

International Nuclear Information System (INIS)

2002-03-01

The Canadian Gas Association (CGA) has expressed concerns regarding how the goal to reduce greenhouse gas emissions can be met. It also has concerns regarding the possible economic impacts of required measures to reduce emissions to 6 per cent below 1990 levels. The CGA argued that since the initial negotiations of the Kyoto Protocol, Canada's greenhouse gas emissions have increased significantly, meaning that if the agreement were to come into force, Canada would have to reduce emissions by about 29 per cent below the currently-projected 2008-2012 level. The report states that 28 per cent of Canada's energy needs are met by natural gas. Excluding energy use in transportation, natural gas contributes more than 40 per cent to Canada's energy portfolio. More than half of Canadian households rely on pipeline services and distribution companies to deliver natural gas for household use. The manufacturing sector relies on natural gas for more than half of its energy needs. Natural gas is a major energy source for the iron/steel, petroleum refining and chemical manufacturing industries. Natural gas is a cleaner-burning fuel than coal or crude oil, and its use results in fewer environmental impacts than other fossil fuels. Vehicles powered by natural gas produce 20 - 30 per cent less carbon dioxide emissions than vehicles powered by gasoline. Pipelines are also a more efficient way of transporting and distributing natural gas than marine transport, railways or trucks. The CGA recommends that policy development should emphasize the environmental benefits of natural gas and recognize its role as a bridge fuel to a cleaner energy-based economy. It also recommends that policies should be developed to encourage the use of natural gas in electricity generation to lower greenhouse gases and air pollutants such as oxides of nitrogen that cause smog

CRITERIA POLLUTANT EMISSIONS FROM INTERNAL COMBUSTION ENGINES IN THE NATURAL GAS INDUSTRY VOLUME 1. TECHNICAL REPORT

Science.gov (United States)

The report summarizes emission factors for criteria pollutants (NOx, CO, CH4, C2H6, THC, NMHC, and NMEHC) from stationary internal combustion engines and gas turbines used in the natural gas industry. The emission factors were calculated from test results from five test campaigns...

The Impact of Wind Power on European Natural Gas Markets

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-06

Due to its clean burning properties, low investment costs and flexibility in production, natural gas is often put forward as the ideal partner fuel for wind power and other renewable sources of electricity generation with strongly variable output. This working paper examines three vital questions associated with this premise: 1) Is natural gas indeed the best partner fuel for wind power? 2) If so, to what extent will an increasing market share of wind power in European electricity generation affect demand for natural gas in the power sector? and 3) Considering the existing European natural gas markets, is natural gas capable of fulfilling this role of partner for renewable sources of electricity?.

Experimental investigation and combustion analysis of a direct injection dual-fuel diesel-natural gas engine

Energy Technology Data Exchange (ETDEWEB)

Carlucci, A.P.; De Risi, A.; Laforgia, D.; Naccarato, F. [Department of Engineering for Innovation, University of Salento, CREA, via per Arnesano, 73100 Lecce (Italy)

2008-02-15

A single-cylinder diesel engine has been converted into a dual-fuel engine to operate with natural gas together with a pilot injection of diesel fuel used to ignite the CNG-air charge. The CNG was injected into the intake manifold via a gas injector on purpose designed for this application. The main performance of the gas injector, such as flow coefficient, instantaneous mass flow rate, delay time between electrical signal and opening of the injector, have been characterized by testing the injector in a constant-volume optical vessel. The CNG jet structure has also been characterized by means of shadowgraphy technique. The engine, operating in dual-fuel mode, has been tested on a wide range of operating conditions spanning different values of engine load and speed. For all the tested operating conditions, the effect of CNG and diesel fuel injection pressure, together with the amount of fuel injected during the pilot injection, were analyzed on the combustion development and, as a consequence, on the engine performance, in terms of specific emission levels and fuel consumption. (author)

State of the art and environmental benefits using methane-hydrogen blends

International Nuclear Information System (INIS)

Faedo, D.

2007-01-01

Hythane is the patented mixture of 15% (by energy content) of hydrogen in CNG: in other proportions the blend is called HCNG. Hydrogen addition to CNG extends the lean burn limit of a natural gas engine, and has the potential to lower the nitrogen oxides emissions and to improve the engine thermal efficiency, with minor hardware changes necessary. This paper reports the benefits of hydrogen to CNG in S.I. engine, and a brief review of the results obtained in this field [it

Laminar burning velocity and Markstein length of nitrogen diluted natural gas/hydrogen/air mixtures at normal, reduced and elevated pressures

Energy Technology Data Exchange (ETDEWEB)

Miao, Haiyan [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China); Institute of High Performance Computing, A-star (Singapore); Ji, Min; Jiao, Qi; Huang, Qian; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Eng., Xi' an Jiaotong University (China)

2009-04-15

Flame propagation of premixed nitrogen diluted natural gas/hydrogen/air mixtures was studied in a constant volume combustion bomb under various initial pressures. Laminar burning velocities and Markstein lengths were obtained for the diluted stoichiometric fuel/air mixtures with different hydrogen fractions and diluent ratios under various initial pressures. The results showed that both unstretched flame speed and unstretched burning velocity are reduced with the increase in initial pressure (except when the hydrogen fraction is 80%) as well as diluent ratio. The velocity reduction rate due to diluent addition is determined mainly by hydrogen fraction and diluent ratio, and the effect of initial pressure is negligible. Flame stability was studied by analyzing Markstein length. It was found that the increase of initial pressure and hydrogen fraction decreases flame stability and the flame tends to be more stable with the addition of diluent gas. Generally speaking, Markstein length of a fuel with low hydrogen fraction is more sensitive to the change of initial pressure than that of a one with high hydrogen fraction. (author)

Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas

International Nuclear Information System (INIS)

Papagiannakis, R.G.; Hountalas, D.T.

2004-01-01

Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high autoignition temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions

Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

Science.gov (United States)

Alanen, Jenni; Simonen, Pauli; Saarikoski, Sanna; Timonen, Hilkka; Kangasniemi, Oskari; Saukko, Erkka; Hillamo, Risto; Lehtoranta, Kati; Murtonen, Timo; Vesala, Hannu; Keskinen, Jorma; Rönkkö, Topi

2017-07-01

Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6-268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9-20 mg kgfuel-1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize - more than half an hour - which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was

Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

Directory of Open Access Journals (Sweden)

J. Alanen

2017-07-01

Full Text Available Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6–268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA formation potential was measured to be 9–20 mg kgfuel−1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize – more than half an hour – which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission

Performance of a diesel engine transformed to spark ignition using natural gas; Desempenho de um motor diesel convertido para utilizacao de gas natural como combustivel

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, Ricardo H.R. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LEDAV/COPPE/UFRJ), RJ (Brazil). Lab. de Ensaios Dinamicos e Analise de Vibracao; Belchior, Carlos R.P. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LMT/COPPE/UFRJ), RJ (Brazil). Lab. de Maquinas Termicas; Sodre, Jose Ricardo [Pontificia Universidade Catolica de Minas Gerais (PUC/Minas), MG (Brazil)

2012-07-01

A zero-dimensional thermodynamic model for a diesel engine converted for dedicated use of natural gas was developed in this work. The computational model covers from the time of closing the inlet valve to the time of opening the exhaust valve and it was divided into three stages (compression, combustion and expansion). A model based on the first law of thermodynamics for closed cycle has been developed to study the performance of the engine. The combustion process was modeled using the equation of Wiebe. It was taken into consideration the convective heat transfer through the walls of the cylinder and the heat transfer coefficient was calculated by the Eichelberg correlation. It was also considered that the thermodynamic properties vary with temperature. To represent the gas mixture behavior inside the cylinder two approaches (Ideal Gas Equation and Van Der Waals's Real Gas Equation) were used and results compared. The computational model was validated with experimental tests. (author)

Low-Engine-Friction Technology for Advanced Natural-Gas Reciprocating Engines

Energy Technology Data Exchange (ETDEWEB)

Victor Wong; Tian Tian; G. Smedley; L. Moughon; Rosalind Takata; J. Jocsak

2006-11-30

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis has been followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. In this program, a detailed set of piston and piston-ring dynamic and friction models have been adapted and applied that illustrate the fundamental relationships among mechanical, surface/material and lubricant design parameters and friction losses. Demonstration of low-friction ring-pack designs in the Waukesha VGF 18GL engine confirmed ring-pack friction reduction of 30-40%, which translates to total engine FEMP (friction mean effective pressure) reduction of 7-10% from the baseline configuration without significantly increasing oil consumption or blow-by flow. The study on surface textures, including roughness characteristics, cross hatch patterns, dimples and grooves have shown that even relatively small-scale changes can have a large effect on ring/liner friction, in some cases reducing FMEP by as much as 30% from a smooth surface case. The measured FMEP reductions were in good agreement with the model predictions. The combined analysis of lubricant and surface design indicates that low-viscosity lubricants can be very effective in reducing friction, subject to component wear for extremely thin oils, which can be mitigated with further lubricant formulation and/or engineered surfaces. Hence a combined approach of lubricant design and appropriate wear reduction offers improved potential for minimum engine friction loss. Testing of low-friction lubricants showed that total engine FMEP reduced by up to {approx}16.5% from the commercial reference oil without significantly increasing oil consumption or blow-by flow. Piston friction studies

Internal combustion engines fueled by natural gas-hydrogen mixtures

Energy Technology Data Exchange (ETDEWEB)

Akansu, S.O.; Kahraman, N. [Erciyes University, Kayseri (Turkey). Engineering Faculty; Dulger, Z. [Kocaeli University (Turkey). Engineering Faculty; Veziroglu, T.N. [University of Miami, Coral Gables, FL (United States). College of Engineering

2004-11-01

In this study, a survey of research papers on utilization of natural gas-hydrogen mixtures in internal combustion engines is carried out. In general, HC, CO{sub 2}, and CO emissions decrease with increasing H{sub 2}, but NO{sub x} emissions generally increase. If a catalytic converter is used, NO{sub x} emission values can be decreased to extremely low levels. Consequently, equivalence zero emission vehicles (EZEV) standards may be reached. Efficiency values vary with H{sub 2} amount, spark timing, compression ratio, equivalence ratio, etc. Under certain conditions, efficiency values can be increased. In terms of BSFC, emissions and BTE, a mixture of low hydrogen percentage is suitable for using. (author)

Some aspects of natural gas and economic development - a short note

International Nuclear Information System (INIS)

Banks, F.E.

1992-01-01

Just because gas is labelled the fuel of the future does not ensure that it will become exactly that; but faith is important. If the world's energy establishments really want to expand their use of natural gas, all the objective conditions exist to make this expansion possible: large and increasing gas supplies; impressive changes in gas-burning technologies; a widespread acceptance of gas by both the general public and environmentalists; and so on. The considerable increase in the supply of gas is probably regarded as bad news by many exporters of gas, but I am not so sure that this will prove to be the case. Instead, a situation may be foreseen where the widely advertized rising supply will tend to encourage demand, since many actual and potential gas users will be inclined to interpret rapidly increasing gas reserves as the forerunner of an extended buyers' market. Two other factors working in favour of natural gas are the growing belief that the remaining reserves of oil are considerably more limited than previously believed and the increase in the value of natural gas due to technological advances being made in gas-burning equipment. The pattern of economic growth and development in Sweden which does not have natural gas and the key role of the electricity sector, is a pointer to countries which do possess gas that they should pay particular attention to its value in electricity generation. (author)

Ultra Clean 1.1MW High Efficiency Natural Gas Engine Powered System

Energy Technology Data Exchange (ETDEWEB)

Zurlo, James; Lueck, Steve

2011-08-31

Dresser, Inc. (GE Energy, Waukesha gas engines) will develop, test, demonstrate, and commercialize a 1.1 Megawatt (MW) natural gas fueled combined heat and power reciprocating engine powered package. This package will feature a total efficiency > 75% and ultra low CARB permitting emissions. Our modular design will cover the 1 – 6 MW size range, and this scalable technology can be used in both smaller and larger engine powered CHP packages. To further advance one of the key advantages of reciprocating engines, the engine, generator and CHP package will be optimized for low initial and operating costs. Dresser, Inc. will leverage the knowledge gained in the DOE - ARES program. Dresser, Inc. will work with commercial, regulatory, and government entities to help break down barriers to wider deployment of CHP. The outcome of this project will be a commercially successful 1.1 MW CHP package with high electrical and total efficiency that will significantly reduce emissions compared to the current central power plant paradigm. Principal objectives by phases for Budget Period 1 include: • Phase 1 – market study to determine optimum system performance, target first cost, lifecycle cost, and creation of a detailed product specification. • Phase 2 – Refinement of the Waukesha CHP system design concepts, identification of critical characteristics, initial evaluation of technical solutions, and risk mitigation plans. Background

Cellular burning in lean premixed turbulent hydrogen-air flames: Coupling experimental and computational analysis at the laboratory scale

International Nuclear Information System (INIS)

Day, M S; Bell, J B; Beckner, V E; Lijewski, M J; Cheng, R K; Tachibana, S

2009-01-01

One strategy for reducing US dependence on petroleum is to develop new combustion technologies for burning the fuel-lean mixtures of hydrogen or hydrogen-rich syngas fuels obtained from the gasification of coal and biomass. Fuel-flexible combustion systems based on lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat and stationary power generation. However, lean premixed flames are highly susceptible to fluid-dynamical combustion instabilities making robust and reliable systems difficult to design. Low swirl burners are emerging as an important technology for meeting design requirements in terms of both reliability and emissions for next generation combustion devices. In this paper, we present simulations of a lean, premixed hydrogen flame stabilized on a laboratory-scale low swirl burner. The simulations use detailed chemistry and transport without incorporating explicit models for turbulence or turbulence/chemistry interaction. Here we discuss the overall structure of the flame and compare with experimental data. We also use the simulation data to elucidate the characteristics of the turbulent flame interaction and how this impacts the analysis of experimental measurements.

Potentials of NO{sub X} emission reduction methods in SI hydrogen engines: Simulation study

Energy Technology Data Exchange (ETDEWEB)

Safari, H.; Jazayeri, S.A. [Department of Mechanical Engineering, K.N. Toosi University of Technology, No.15, Pardis Street, Vanak Square, Tehran (Iran); Ebrahimi, R. [Department of Aerospace Engineering, K.N. Toosi University of Technology, 4th Tehranpars Square, East Vafadar Street, Tehran (Iran)

2009-01-15

The ever increasing cost of hydrocarbon fuels and more stringent emission standards may resolve challenges in producing hydrogen and using it as an alternative fuel in industries. Internal combustion engines are well-established technology and hydrogen fuel in such engines is considered as an attractive choice in exploiting clean, efficient and renewable hydrogen energy. This work presents an improved thermo-kinetics model for simulation of hydrogen combustion in SI engines. The turbulent propagating flame is modeled using turbulent burning velocity model. During combustion the charge is divided into three zones containing unburned charge, flame and burned gas. The adiabatic flame is assumed to be in thermodynamic equilibrium while the detailed chemical kinetics scheme is considered for burned and unburned zones. The results were first validated against published experiments. Good agreements were obtained between simulation and experiment for varying equivalence ratio, ignition timing and compression ratio. Detailed analysis of engine NO{sub X} emission was performed afterward. The lean-burn and EGR strategies' potentials were examined by the current model. The effects of different amounts of cooled dry EGR and hot wet EGR on the NO{sub X} emission, engine power output and indicated thermal efficiency were investigated and compared theoretically. (author)

Natural gas industry R and D

International Nuclear Information System (INIS)

Pavan, S.

1992-01-01

The last three decades have witnessed significant developments in engineering relative to the distribution and use of natural gas. This paper reviews these developments which, in natural gas distribution, include - polyethylene conduits, the use of radar to trace buried conduits, telemetering, innovative pressure reducing techniques and equipment, optimized retrofitting of buried pipelines, leak detection techniques, and energy recovery systems applied to pressure reducing operations. Relative to the efficient combustion and new uses of natural gas, the paper reviews the state-of-the-art in the design of compact wall mounted gas fired boilers for building space heating, gas fuelled space heating ventilation and air conditioning systems, and natural gas fed fuel cells

Use of catalytic reforming to aid natural gas HCCI combustion in engines: experimental and modelling results of open-loop fuel reforming

Energy Technology Data Exchange (ETDEWEB)

Peucheret, S.; Wyszynski, M.L.; Lehrle, R.S. [Future Power Systems Group, Mechanical Engineering, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Golunski, S. [Johnson Matthey, Technology Centre, Blount' s Court, Sonning Common, Reading RG4 9NH (United Kingdom); Xu, H. [Jaguar Land Rover Research, Jaguar Land Rover W/2/021, Abbey Road, Coventry CV3 4LF (United Kingdom)

2005-12-01

The potential of the homogeneous charge compression ignition (HCCI) combustion process to deliver drastically reduced emissions of NO{sub x} and improved fuel economy from internal combustion engines is well known. The process is, however, difficult to initiate and control, especially when methane or natural gas are used as fuel. To aid the HCCI combustion of natural gas, hydrogen addition has been successfully used in this study. This hydrogen can be obtained from on-line reforming of natural gas. Methane reforming is achieved here by reaction with engine exhaust gas and air in a small scale monolith catalytic reactor. The benchmark quantity of H{sub 2} required to enhance the feasibility and engine load range of HCCI combustion is 10%. For low temperature engine exhaust gas, typical for HCCI engine operating conditions, experiments show that additional air is needed to produce this quantity. Experimental results from an open-loop fuel exhaust gas reforming system are compared with two different models of basic thermodynamic equilibria calculations. At the low reactor inlet temperatures needed for the HCCI application (approx. 400 deg C) the simplified three-reaction thermodynamic equilibrium model is in broad agreement with experimental results, while for medium (550-650 deg C) inlet temperature reforming with extra air added, the high hydrogen yields predicted from the multi-component equilibrium model are difficult to achieve in a practical reformer. (author)

CRITERIA POLLUTANT EMISSIONS FROM INTERNAL COMBUSTION ENGINES IN THE NATURAL GAS INDUSTRY VOLUME II. APPENDICES A-I

Science.gov (United States)

The report summarizes emission factors for criteria pollutants (NOx, CO, CH4, C2H6, THC, NMHC, and NMEHC) from stationary internal combustion engines and gas turbines used in the natural gas industry. The emission factors were calculated from test results from five test campaigns...

Experimental Evaluation of SI Engine Operation Supplemented by Hydrogen Rich Gas from a Compact Plasma Boosted Reformer

International Nuclear Information System (INIS)

J. B. Green, Jr.; N. Domingo; J. M. E. Storey; R.M. Wagner; J.S. Armfield; L. Bromberg; D. R. Cohn; A. Rabinovich; N. Alexeev

2000-01-01

It is well known that hydrogen addition to spark-ignited (SI) engines can reduce exhaust emissions and increase efficiency. Micro plasmatron fuel converters can be used for onboard generation of hydrogen-rich gas by partial oxidation of a wide range of fuels. These plasma-boosted microreformers are compact, rugged, and provide rapid response. With hydrogen supplement to the main fuel, SI engines can run very lean resulting in a large reduction in nitrogen oxides (NO x ) emissions relative to stoichiometric combustion without a catalytic converter. This paper presents experimental results from a microplasmatron fuel converter operating under variable oxygen to carbon ratios. Tests have also been carried out to evaluate the effect of the addition of a microplasmatron fuel converter generated gas in a 1995 2.3-L four-cylinder SI production engine. The tests were performed with and without hydrogen-rich gas produced by the plasma boosted fuel converter with gasoline. A one hundred fold reduction in NO x due to very lean operation was obtained under certain conditions. An advantage of onboard plasma-boosted generation of hydrogen-rich gas is that it is used only when required and can be readily turned on and off. Substantial NO x reduction should also be obtainable by heavy exhaust gas recirculation (EGR) facilitated by use of hydrogen-rich gas with stoichiometric operation

Natural gas industry and its effects on the environment

International Nuclear Information System (INIS)

Al-Masri, M. S.; Kejeijan, B.

2008-01-01

The discoveries of natural gas have increased during the last ten years in Syria, These increases lead to the necessity of knowing the effects of this industry on the environment. Syrian Arabic Republic has been planning to convert most of the current electric of plants to natural gas in addition to future plans to export natural gas to the surrounding countries. In addition, the government is working on the use of LPG gas in automobiles. However, environmentally, the importance of natural gas is due to the followings: 1- Natural gas, when burned, emits lower quantities of greenhouse gases and criteria pollutants per unit of energy produced than to other fossil fuels. This occurs in part because natural gas is more fully combusted, and in part because natural gas contains fewer impurities than any other fossil fuel. 2-The amount of carbon dioxide produced from the combustion of natural gas is less than the amount produced from the combustion of other fossil fuels to produce the same amount of heat. One of the important uses of natural gas is in the transportation since natural gas does not produce during combustion toxic compounds which are usually produced during the combustion of diesel and benzene. therefore natural gas is seen and considered as an important fuel to address environmental concerns. (author)

Modelling and Simulation of Gas Engines Using Aspen HYSYS

Directory of Open Access Journals (Sweden)

M. C. Ekwonu

2013-12-01

Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

Engineered Sulfur‐Resistant Catalyst System with an Assisted Regeneration Strategy for Lean‐Burn Methane Combustion

Science.gov (United States)

Kallinen, Kauko; Maunula, Teuvo; Suvanto, Mika

2018-01-01

Abstract Catalytic combustion of methane, the main component of natural gas, is a challenge under lean‐burn conditions and at low temperatures owing to sulfur poisoning of the Pd‐rich catalyst. This paper introduces a more sulfur‐resistant catalyst system that can be regenerated during operation. The developed catalyst system lowers the barrier that has restrained the use of liquefied natural gas as a fuel in energy production. PMID:29780434

CFD analysis of NOx reduction by domestic natural gas added to coal combustion

Energy Technology Data Exchange (ETDEWEB)

Bar-Ziv, E.; Yasur, Y.; Chudnovsky, B. [Ben-Gurion University of the Negev, Beer-Sheva (Israel). Dept. of Mechanical Engineering and Inst. for Applied Research

2004-07-01

To date, Israel's electrical energy has been based only on imported fuels. However, with the recently discovered natural gas in the Ashqulon shores, Israel can examine the benefits to its energy resources, environment, and economy of blending its domestic natural gas with imported coal. As for using natural gas, the proposal is to burn it in existing IEC coal-fired boilers in order to significantly reduce NOx emission by reburning. An important aspect is to provide retrofitting in existing IEC boilers by replacing a fraction of the coal by natural gas. This would allow the purchase of coal with a wide range of parameters, which is less expensive. Hence, mixed gas-coal burning would benefit Israel. The authors have made numerical simulations in order to study the optimal conditions of operation and evaluate the economic as well as environmental benefits. Indeed, extensive simulations have shown that there is a significant reduction of NOx emission, as expected, with the addition of relatively small amounts of natural gas. Experiments will now be carried out in a test facility that will provide accurate physicochemical properties of the mixed fuel for more reliable simulations. 19 refs., 6 figs., 1 tab.

Comparative evaluation of a natural gas expansion plant integrated with an IC engine and an organic Rankine cycle

International Nuclear Information System (INIS)

Kostowski, Wojciech J.; Usón, Sergio

2013-01-01

Highlights: • Comparison of natural gas expansion systems integrated with gas boiler, ICE and ORC. • Expansion systems replace the throttling process in pressure regulating stations. • 5 System performance indicators based on the 1st and 2nd law are defined. • Exergy efficiency was calculated from the fuel-product approach. • ORC system yields highest exergy efficiency 52.6% and performance ratio of 0.771. - Abstract: The aim of the paper is to propose and evaluate an innovative exergy recovery system for natural gas expansion, based on the integration of an internal combustion engine (ICE) and an organic Rankine cycle (ORC), and to compare it with other alternatives. Natural gas expansion plants are a substantial improvement to the conventional gas pressure reduction stations, based on the throttling process, since the available physical exergy of pressurized gas is converted into mechanical energy by means of an expansion machine (turbine or piston expander) instead of being lost in the throttling process. However, due to the hydrate formation problem the gas has to be pre-heated prior to the expansion, which diminishes the system performance. An efficient method for performing this pre-heating is by the proposed system that comprises an ICE and an ORC: Pre-heating of natural gas is carried out partially directly by the co-generation module, via the engine cooling cycle, and partially indirectly, by means of the engine exhaust gases, which supply heat for the ORC, while the ORC condenser is connected with the lowest stage of natural gas pre-heating. Other alternatives are the use of an ICE without ORC, the use of a boiler, and even expansion in a throttling valve. The paper evaluates the performance of the aforementioned four configurations by means of both energy and exergy analysis. Several alternative performance indicators have been defined, calculated and discussed. Sources of irreversibilities have been identified by means of exergy analysis

Development and validation of a multi-zone combustion model for performance and nitric oxide formation in syngas fueled spark ignition engine

International Nuclear Information System (INIS)

Rakopoulos, C.D.; Michos, C.N.

2008-01-01

The development of a zero-dimensional, multi-zone combustion model is presented for predicting the performance and nitric oxide (NO) emissions of a spark ignition (SI) engine. The model is validated against experimental data from a multi-cylinder, four-stroke, turbocharged and aftercooled, SI gas engine running with syngas fuel. This alternative fuel, the combustible part of which consists mainly of CO and H 2 with the rest containing non-combustible gases, has been recently identified as a promising substitute of fossil fuels in view of environmentally friendly engine operation. The basic concept of the model is the division of the burned gas into several distinct zones, unlike the simpler two-zone models, for taking into account the temperature stratification of the burned mixture during combustion. This is especially important for accurate NO emissions predictions, since NO formation is strongly temperature dependent. The multi-zone formulation provides the chemical species concentrations gradient existing in the burned zones, as well as the relative contribution of each burned zone to the total in-cylinder NO formation. The burning rate required as input to the model is expressed as a Wiebe function, fitted to experimentally derived burn rates. All model's constants are calibrated at one operating point and then kept unchanged. Zone-resolved combustion related information is obtained, assisting in the understanding of the complex phenomena occurring during combustion in SI engines. Combustion characteristics of the lean-burn gas engine tested are provided for the complete load range, aiding the interpretation of its performance and knocking tendency. Computed NO emissions from the multi-zone model for various values of the engine load (i.e. air-fuel ratios) are presented and found to be in good agreement with the respective experimental ones, providing confidence for the predictive capability of the model. The superiority of the multi-zone model over its two

Natural gas for utility generation

International Nuclear Information System (INIS)

Moore, T.

1992-01-01

Forecasters predict that natural gas will be the dominant fuel choice for utility capacity additions in the coming decade and that power generation will be by far the largest growth market for gas sales. While gas's low emissions, high efficiency potential, and present low cost argue persuasively for a surge in gas-fired generation, many utilities have been slow to commit to a gas future, citing reasoned concern about long-term price trends and the ability of gas suppliers to deliver the fuel where and when it will be needed. Meanwhile, the relatively low cost of gas-fired units is providing an opportunity for independent power producers to compete strongly with utilities for generation contracts. EPRI studies suggest that a sound, competitive strategy will be based not on how much gas a utility burns, but rather on how this capacity fits into its overall generating mix at various fuel price levels. Gas suppliers will need to pay special attention to the operating needs of power generators if they are to solidify this important market

COMBUSTION AND PERFORMANCE CHARACTERISTICS OF A SMALL SPARK IGNITION ENGINE FUELLED WITH HCNG

OpenAIRE

A. SONTHALIA; C. RAMESHKUMAR; U. SHARMA; A. PUNGANUR; S. ABBAS

2015-01-01

Due to environmental concerns and fossil fuel depletion, large scale researches were carried out involving the use of natural gas in internal combustion engines. Natural gas is a clean burning fuel that is available from large domestic natural reserve. When it is used as a fuel in SI engines, it reduces emissions to meet EURO-III norms with carburettors and EURO-IV norms with manifold injection. Countries like India with fewer natural fossil fuel reserves depend heavily on oil imported fro...

PERFORMANCE, EMISSION, AND COMBUSTION CHARACTERISTICS OF A CI ENGINE USING LIQUID PETROLEUM GAS AND NEEM OIL IN DUAL FUEL MODE

Directory of Open Access Journals (Sweden)

Palanimuthu Vijayabalan

2010-01-01

Full Text Available Increased environmental awareness and depletion of resources are driving the industries to develop viable alternative fuels like vegetable oils, compresed natural gas, liquid petroleum gas, producer gas, and biogas in order to provide suitable substitute to diesel for compression ignition engine. In this investigation, a single cylinder, vertical, air-cooled diesel engine was modified to use liquid petroleum gas in dual fuel mode. The liquefied petroleum gas, was mixed with air and supplied through intake manifold. The liquid fuel neem oil or diesel was injected into the combustion chamber. The performance, emission, and combustion characteristics were studied and compared for neat fuel and dual fuel mode. The experimental results on dual fuel engine show a reduction in oxides of nitrogen up to 70% of the rated power and smoke in the entire power range. However the brake thermal efficiency was found decreased in low power range due to lower calorific value of liquid petroleum gas, and increase in higher power range due to the complete burning of liquid petroleum gas. Hydrocarbon and carbon monoxide emissions were increased significantly at lower power range and marginal variation in higher power range.

Reversing flow catalytic converter for a natural gas/diesel dual fuel engine

Energy Technology Data Exchange (ETDEWEB)

Liu, E.; Checkel, M.D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering; Hayes, R.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering; Zheng, M.; Mirosh, E. [Alternative Fuel Systems Inc., Calgary, AB (Canada)

2001-07-01

An experimental and modelling study was performed for a reverse flow catalytic converter attached to a natural gas/diesel dual fuel engine. The catalytic converter had a segmented ceramic monolith honeycomb substrate and a catalytic washcoat containing a predominantly palladium catalyst. A one-dimensional single channel model was used to simulate the operation of the converter. The kinetics of the CO and methane oxidation followed first-order behaviour. The activation energy for the oxidation of methane showed a change with temperature, dropping from a value of 129 to 35 kJ/mol at a temperature of 874 K. The reverse flow converter was able to achieve high reactor temperature under conditions of low inlet gas temperature, provided that the initial reactor temperature was sufficiently high. (author)

Natural gas vehicles. An option for Europe

International Nuclear Information System (INIS)

Engerer, Hella; Horn, Manfred

2010-01-01

In Europe natural gas vehicles play a minor role. A decisive reason for this is the dependence of most European countries from gas imports. Except for Italy, there is no tradition to use natural gas as fuel. In addition, there is a lack of infrastructure (e.g. fuelling stations). In contrast to Europe, in Latin American and Asian countries natural gas vehicles are widespread. Some countries foster natural gas vehicles because they have own gas resources. Many countries must reduce the high air pollution in big cities. Environmental reasons are the main motive for the use of natural gas vehicles in Europe. In last years, high oil prices stimulated the use of natural gas as fuel. European governments have developed incentives (e.g. tax reductions) to foster natural gas vehicles. However, the focus is on hybrid technology and the electric car, which, however, need further technical improvement. In contrast, the use of natural gas in conventional engines is technically mature. Additional gas imports can be avoided by further improvements of energy efficiency and the use of renewable energy. In sum, the market penetration of natural gas as fuel should be promoted in Europe. (author)

Natural gas utilization in Santa Cruz thermal-electric power; A utilizacao de gas natural em Santa Cruz

Energy Technology Data Exchange (ETDEWEB)

Azevedo, Mauricio F. de.; Lundeqvist, Carl G; Gomes, Gerson; Almeida, A E

1994-12-31

Use of natural gas as an alternative energy source on the thermo electric power plant of Santa Cruz are presented. Economic studies on hydroelectric power plants to use thermal generators during low water supply periods, costs of natural gas as a alternative energy fuel, and the engineer services to the conversion of fuel oil system, are discussed. 5 figs., 6 tabs.

Two-stage combustion for reducing pollutant emissions from gas turbine combustors

Science.gov (United States)

Clayton, R. M.; Lewis, D. H.

1981-01-01

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

Use of a single-zone thermodynamic model with detailed chemistry to study a natural gas fueled homogeneous charge compression ignition engine

International Nuclear Information System (INIS)

Zheng Junnian; Caton, Jerald A.

2012-01-01

Highlights: ► Auto-ignition characteristics of a natural gas fueled HCCI engine. ► Engine speed had the greatest effect on the auto-ignition process. ► Increases of C 2 H 6 or C 3 H 8 improved the auto-ignition process. ► Engine performance was not sensitive to small changes in C 2 H 6 or C 3 H 8 . ► Nitric oxides concentrations decreased as engine speed or EGR level was increased. - Abstract: A single zone thermodynamic model with detailed chemical kinetics was used to simulate a natural gas fueled homogeneous charge compression ignition (HCCI) engine. The model employed Chemkin and used chemical kinetics for natural gas with 53 species and 325 reactions. This simulation was used to complete analyses for a modified 0.4 L single cylinder engine. The engine possessed a compression ratio of 21.5:1, and had a bore and stroke of 86 and 75 mm, respectively. Several sets of parametric studies were completed to investigate the minimal initial temperature, engine performance, and nitric oxide emissions of HCCI engine operation. The results show significant changes in combustion characteristics with varying engine operating conditions. Effects of varying equivalence ratios (0.3–1.0), engine speeds (1000–4000 RPM), EGR (0–40%), and fuel compositions were determined and analyzed in detail. In particular, every 0.1 increase in equivalence ratio or 500 rpm increase in engine speed requires about a 5 K higher initial temperature for complete combustion, and leads to around 0.7 bar increase in IMEP.

METHOD OF CONVERSION OF HIGH- AND MIDDLE-SPEED DIESEL ENGINES INTO GAS DIESEL ENGINES

Directory of Open Access Journals (Sweden)

Mikhail G. Shatrov

2017-12-01

Full Text Available The paper aims at the development of fuel supply and electronic control systems for boosted high- and middle-speed transport engines. A detailed analysis of different ways of converting diesel engine to operate on natural gas was carried out. The gas diesel process with minimized ignition portion of diesel fuel injected by the Common Rail (CR system was selected. Electronic engine control and modular gas feed systems which can be used both on high- and middle-speed gas diesel engines were developed. Also diesel CR fuel supply systems were developed in cooperation with the industrial partner, namely, those that can be mounted on middle-speed diesel and gas diesel engines. Electronic control and gas feed systems were perfected using modeling and engine tests. The high-speed diesel engine was converted into a gas diesel one. After perfection of the gas feed and electronic control systems, bench tests of the high-speed gas diesel engine were carried out showing a high share of diesel fuel substitution with gas, high fuel efficiency and significant decrease of NOх and СО2 emissions.

Role of natural gas in meeting an electric sector emissions ...

Science.gov (United States)

With advances in natural gas extraction technologies, there is an increase in availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but uncertainties exist in the amount of methane leakage occurring upstream in the extraction and production of natural gas. At high leakage levels, these methane emissions could outweigh the benefits of switching from coal to natural gas. This analysis uses the MARKAL linear optimization model to compare the carbon emissions profiles and system-wide global warming potential of the U.S. energy system over a series of model runs in which the power sector is asked to meet a specific CO2 reduction target and the availability of natural gas changes. Scenarios are run with a range of upstream methane emission leakage rates from natural gas production. While the total CO2 emissions are reduced in most scenarios, total greenhouse gas emissions show an increase or no change when both natural gas availability and methane emissions from natural gas production are high. Article presents summary of results from an analyses of natural gas resource availability and power sector emissions reduction strategies under different estimates of methane leakage rates during natural gas extraction and production. This was study was undertaken as part of the Energy Modeling Forum Study #31:

Improving the performance of dual fuel engines running on natural gas/LPG by using pilot fuel derived from jojoba seeds

Energy Technology Data Exchange (ETDEWEB)

Selim, Mohamed Y.E. [Mechanical Engineering Department, College of Engineering, UAE University, Jimmi, Al-Ain, P.O. Box 17555, Abu Dhabi (United Arab Emirates); Radwan, M.S.; Saleh, H.E. [Mechanical Power Engineering Department, Faculty of Engineering at Mattaria, Helwan University, Cairo (Egypt)

2008-06-15

The use of jojoba methyl ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or liquefied petroleum gas (LPG) at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or LPG as the main fuel and jojoba methyl ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic variability data of 100 engine cycles in terms of maximum pressure and its pressure rise rate average and standard deviation. The tests examined the following engine parameters: gaseous fuel type, engine speed and load, pilot fuel injection timing, pilot fuel mass and compression ratio. Results showed that using the jojoba fuel with its improved properties has improved the dual fuel engine performance, reduced the combustion noise, extended knocking limits and reduced the cyclic variability of the combustion. (author)

On the Experimental and Theoretical Investigations of Lean Partially Premixed Combustion, Burning Speed, Flame Instability and Plasma Formation of Alternative Fuels at High Temperatures and Pressures

Science.gov (United States)

Askari, Omid

This dissertation investigates the combustion and injection fundamental characteristics of different alternative fuels both experimentally and theoretically. The subjects such as lean partially premixed combustion of methane/hydrogen/air/diluent, methane high pressure direct-injection, thermal plasma formation, thermodynamic properties of hydrocarbon/air mixtures at high temperatures, laminar flames and flame morphology of synthetic gas (syngas) and Gas-to-Liquid (GTL) fuels were extensively studied in this work. These subjects will be summarized in three following paragraphs. The fundamentals of spray and partially premixed combustion characteristics of directly injected methane in a constant volume combustion chamber have been experimentally studied. The injected fuel jet generates turbulence in the vessel and forms a turbulent heterogeneous fuel-air mixture in the vessel, similar to that in a Compressed Natural Gas (CNG) Direct-Injection (DI) engines. The effect of different characteristics parameters such as spark delay time, stratification ratio, turbulence intensity, fuel injection pressure, chamber pressure, chamber temperature, Exhaust Gas recirculation (EGR) addition, hydrogen addition and equivalence ratio on flame propagation and emission concentrations were analyzed. As a part of this work and for the purpose of control and calibration of high pressure injector, spray development and characteristics including spray tip penetration, spray cone angle and overall equivalence ratio were evaluated under a wide range of fuel injection pressures of 30 to 90 atm and different chamber pressures of 1 to 5 atm. Thermodynamic properties of hydrocarbon/air plasma mixtures at ultra-high temperatures must be precisely calculated due to important influence on the flame kernel formation and propagation in combusting flows and spark discharge applications. A new algorithm based on the statistical thermodynamics was developed to calculate the ultra-high temperature plasma

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

Science.gov (United States)

Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

2015-01-01

In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing", evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

Pollutant Formation during the Occurrence of Flame Instabilities under Very-Lean Combustion Conditions in a Liquid-Fuel Burner

Directory of Open Access Journals (Sweden)

Maria Grazia De Giorgi

2017-03-01

Full Text Available Recent advances in gas turbine combustor design are aimed at achieving low exhaust emissions, hence modern aircraft jet engines are designed with lean-burn combustion systems. In the present work, we report an experimental study on lean combustion in a liquid fuel burner, operated under a non-premixed (single point injection regime that mimics the combustion in a modern aircraft engine. The flame behavior was investigated in proximity of the blow-out limit by an intensified high rate Charge-Coupled Device (CCD camera equipped with different optical filters to selectively record single species chemiluminescence emissions (e.g., OH*, CH*. Analogous filters were also used in combination with photomultiplier (PMT tubes. Furthermore this work investigates well-mixed lean low NOx combustion where mixing is good and generation of solid carbon particulate emissions should be very low. An analysis of pollutants such as fine particles and gaseous emissions was also performed. Particle number concentrations and size distributions were measured at the exhaust of the combustion chamber by two different particle size measuring instruments: a scanning mobility particle sizer (SMPS and an Electrical Low Pressure Impactor (ELPI. NOx concentration measurements were performed by using a cross-flow modulation chemiluminescence detection system; CO concentration emissions were acquired with a Cross-flow modulation Non-dispersive infrared (NDIR absorption method. All the measurements were completed by diagnostics of the fundamental combustor parameters. The results herein presented show that at very-lean conditions the emissions of both particulate matter and CO was found to increase most likely due to the occurrence of flame instabilities while the NOx were observed to reduce.

Influence of Injector Location on Part-Load Performance Characteristics of Natural Gas Direct-Injection in a Spark Ignition Engine

Energy Technology Data Exchange (ETDEWEB)

Sevik, James [Argonne National Lab. (ANL), Argonne, IL (United States); Pamminger, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Wallner, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Scarcelli, Riccardo [Argonne National Lab. (ANL), Argonne, IL (United States); Boyer, Brad [Ford Motor Co., Detroit, MI (United States); Wooldridge, Steven [Ford Motor Co., Detroit, MI (United States); Hall, Carrie [Illinois Inst. of Technology, Chicago, IL (United States); Miers, Scott [Michigan Technological Univ., Houghton, MI (United States)

2016-04-05

Interest in natural gas as an alternative fuel source to petroleum fuels for light-duty vehicle applications has increased due to its domestic availability and stable price compared to gasoline. With its higher hydrogen-to-carbon ratio, natural gas has the potential to reduce engine out carbon dioxide emissions, which has shown to be a strong greenhouse gas contributor. For part-load conditions, the lower flame speeds of natural gas can lead to an increased duration in the inflammation process with traditional port-injection. Direct-injection of natural gas can increase in-cylinder turbulence and has the potential to reduce problems typically associated with port-injection of natural gas, such as lower flame speeds and poor dilution tolerance. A study was designed and executed to investigate the effects of direct-injection of natural gas at part-load conditions. Steady-state tests were performed on a single-cylinder research engine representative of current gasoline direct-injection engines. Tests were performed with direct-injection in the central and side location. The start of injection was varied under stoichiometric conditions in order to study the effects on the mixture formation process. In addition, exhaust gas recirculation was introduced at select conditions in order to investigate the dilution tolerance. Relevant combustion metrics were then analyzed for each scenario. Experimental results suggest that regardless of the injector location, varying the start of injection has a strong impact on the mixture formation process. Delaying the start of injection from 300 to 120°CA BTDC can reduce the early flame development process by nearly 15°CA. While injecting into the cylinder after the intake valves have closed has shown to produce the fastest combustion process, this does not necessarily lead to the highest efficiency, due to increases in pumping and wall heat losses. When comparing the two injection configurations, the side location shows the best

Development of a 1200 KW/CYL low pressure dual fuel engine for LNG carriers

Energy Technology Data Exchange (ETDEWEB)

Grosshans, G. [S.E.M.T.-Pielstick, Thermodynamical Project Dept. (France)

1998-12-31

This paper describes the design and feasibility tests of a 570 mm bore 4 stroke low pressure (L.P.) dual fuel engine rated at 20.9 bar BMEP meant for the propulsion of LNG carriers. The basic design features which are to be in accordance with classification societies safety rules are described: individual electro hydraulic valves located in the air manifold ducts, pilot injection, monitoring system etc. The engine capability to burn variable liquid/gas fuel proportions have been investigated with diesel oil and heavy fuel and possible running zones are defined. This ensures the possibility of the engine to cope with the different boil off gas quantity emanating from the ship`s tank during her loaded - and ballast - journeys. With the very lean setting of this engine, no adverse influence of the high ash lube-oil additives were found during the tests. Further tests are necessary to confirm that possible more significant fouling of the combustion chamber is still acceptable. (au)

Evaluation of burn injuries related to liquefied petroleum gas.

Science.gov (United States)

Tarim, Mehmet Akin

2014-01-01

Liquefied petroleum gas (LPG) is a fuel that is widely used for domestic, agricultural, and industrial purposes. LPG is also commonly used in restaurants, industries, and cars; however, the home continues to be the main site for accidents. In Turkey, the increased usage of LPG as a cooking or heating fuel has resulted in many burn injuries from LPG mishaps. Between January 2000 and June 2011, 56 LPG-burned patients were compared with 112 flame-burned patients. There were no significant differences with respect to the mean age, sex, hospitalization time, and mortality in both groups. In the LPG-caused burn cases, 41 burns (73.2%) occurred at home, seven (12.5) were work-related mishaps, and eight (14.3) were associated with car accidents. The majority of the LPG burns (82%, 46 patients) resulted from a gas leak, and 18% of them were related to the failure to close LPG tubes in the patients' kitchens (10 patients). Burns to the face and neck (82 vs 67%, P = .039) and upper (62 vs 23%, P = .000) and lower (70 vs 45%, P = .002) extremities were significantly higher in LPG-caused burn cases than flame-burned cases. General awareness regarding the risk of LPG and first aid for burns appears to be lacking. The LPG delivery system should be standardized throughout countries that widely use LPG.

Prediction of major pollutants emission in direct injection dual-fuel diesel and natural-gas engines

International Nuclear Information System (INIS)

Pirouzpanah, V.; Kashani, B.O.

2000-01-01

The dual-fuel diesel engine is a conventional diesel engine in which much of the energy released, hence power, comes from the combustion of gaseous fuel such as natural gas. The exhaust emission characteristics of the dual-fuel diesel engine needs further refinements, particularly in terms of reduction of Unburnt Hydrocarbons and Carbon Monoxide (CO) emission, because the concentration of these pollutants are higher than that of the baseline diesel engine. Furthermore, the combustion process in a typical dual-fuel diesel engine tends to be complex, showing combination of the problems encountered both in diesel and spark ignition engines. In this work, a computer code has been modified for simulation of dual-fuel diesel engine combustion process. This model simulates dual-fuel diesel engine combustion by using a Multi-Zone Combustion Model for diesel pilot jet combustion and a conventional spark ignition combustion model for modelling of combustion of premixed gas/air charge. Also, in this model, there are four submodels for prediction of major emission pollutants such as: Unburnt Hydrocarbons, No, Co and soot which are emitted from dual-fuel diesel engine. For prediction of formation and oxidation rates of pollutants, relevant s conventional kinetically-controlled mechanisms and mass balances are used. the model has been verified by experimental data obtained from a heavy-duty truck and bus diesel engines. The comparison shows that, there exist good agreements between the experimental and predicted results from the dual-fuel diesel engine

Développement d'un moteur 4-soupapes fonctionnant en mélange dilué. Une nouvelle approche basée sur l'optimisation de l'aérodynamique interne Application of Flow Field Optimization to Lean Burn Engine Development. A New Approach Based on Internal Flow Field Optimization

Directory of Open Access Journals (Sweden)

Henriot S.

2006-11-01

entre 0,60 et 0,70 suivant la charge et le régime. La diminution des émissions d'oxydes d'azote qui en résulte atteint en moyenne sur des points représentatifs du cycle ECE15 74 % par rapport au fonctionnement à la stoechiométrie. Enfin, des essais avec recyclage des gaz d'échappement ont démontré le potentiel de la solution optimisée d'un point de vue aérodynamique à tout mode de fonctionnement en mélange dilué. The constraints that must be accounted for inbuilding a new engine are increasing. It is necessary to contend with user demands for performance, while improving efficiency, limiting pollutant emissions and reducing knock sensitivity. Given the number of parameters to be taken into account, the response to these demands would require large investments in time and resources if conventional development methods (which usually follow an empirical approach were applied. The purpose of this research supported by Groupement Scientifique Moteur (GSM was to design a lean-burn sparkignition engine with the object of reducing pollutant emissions and fuel consumption. We try to develop a promising new approach that follows a scientific methodology based in particular on the use of predictive computer codes. The objective of this project is to design an engine that runs on a lean or possibly dilute mixture that will meet European pollution regulations. This lean-burn solution, combined with oxidation catalysis, is considered as an alternative to threeway catalysis, which imposes operation at stoichiometry. The original configuration is a 4-valve engine. One of the advantages this engine offers is great flexibility in changing the inlet conditions. This provides a way of optimizing internal fluid motion, which turns out to be a determining factor in the ability to operate with a lean or dilute mixture. The operation of an engine with a lean or dilute mixture results in substantially reducing nitrogen oxide (NOx emissions, virtually eliminating carbon dioxide (CO

Contact heating of water products of combustion of natural gas

Energy Technology Data Exchange (ETDEWEB)

Aronov, I Z

1978-01-01

The USSR's NIIST examined the processes and equipment for heating water by submerged combustion using natural gas. Written for engineers involved with the design and application of thermal engineering equipment operating with natural gas, the book emphasizes equipment, test results, and methods of calculating heat transfer for contact gas economizers developed by Scientific Research Institute of Sanitary Engineering and other Soviet organizations. The economic effectiveness of submerged-combustion heating depends on several factors, including equipment design. Recommendations cover cost-effective designs and applications of contact economizers and boilers.

A Review of Materials for Gas Turbines Firing Syngas Fuels

Energy Technology Data Exchange (ETDEWEB)

Gibbons, Thomas [ORNL; Wright, Ian G [ORNL

2009-05-01

Following the extensive development work carried out in the 1990's, gas turbine combined-cycle (GTCC) systems burning natural gas represent a reliable and efficient power generation technology widely used in many parts of the world. A critical factor was that, in order to operate at the high turbine entry temperatures required for high efficiency operation, aero-engine technology, i.e., single-crystal blades, thermal barrier coatings, and sophisticated cooling techniques had to be rapidly scaled up and introduced into these large gas turbines. The problems with reliability that resulted have been largely overcome, so that the high-efficiency GTCC power generation system is now a mature technology, capable of achieving high levels of availability. The high price of natural gas and concern about emission of greenhouse gases has focused attention on the desirability of replacing natural gas with gas derived from coal (syngas) in these gas turbine systems, since typical systems analyses indicate that IGCC plants have some potential to fulfil the requirement for a zero-emissions power generation system. In this review, the current status of materials for the critical hot gas path parts in large gas turbines is briefly considered in the context of the need to burn syngas. A critical factor is that the syngas is a low-Btu fuel, and the higher mass flow compared to natural gas will tend to increase the power output of the engine. However, modifications to the turbine and to the combustion system also will be necessary. It will be shown that many of the materials used in current engines will also be applicable to units burning syngas but, since the combustion environment will contain a greater level of impurities (especially sulfur, water vapor, and particulates), the durability of some components may be prejudiced. Consequently, some effort will be needed to develop improved coatings to resist attack by sulfur-containing compounds, and also erosion.

Sector Tests of a Low-NO(sub x), Lean, Direct- Injection, Multipoint Integrated Module Combustor Concept Conducted

Science.gov (United States)

Tacina, Robert R.; Wey, Chang-Lie; Laing, Peter; Mansour, Adel

2002-01-01

The low-emissions combustor development described is directed toward advanced high pressure aircraft gas-turbine applications. The emphasis of this research is to reduce nitrogen oxides (NOx) at high-power conditions and to maintain carbon monoxide and unburned hydrocarbons at their current low levels at low power conditions. Low-NOx combustors can be classified into rich-burn and lean-burn concepts. Lean-burn combustors can be further classified into lean-premixed-prevaporized (LPP) and lean direct injection (LDI) concepts. In both concepts, all the combustor air, except for liner cooling flow, enters through the combustor dome so that the combustion occurs at the lowest possible flame temperature. The LPP concept has been shown to have the lowest NOx emissions, but for advanced high-pressure-ratio engines, the possibility of autoignition or flashback precludes its use. LDI differs from LPP in that the fuel is injected directly into the flame zone, and thus, it does not have the potential for autoignition or flashback and should have greater stability. However, since it is not premixed and prevaporized, good atomization is necessary and the fuel must be mixed quickly and uniformly so that flame temperatures are low and NOx formation levels are comparable to those of LPP. The LDI concept described is a multipoint fuel injection/multiburning zone concept. Each of the multiple fuel injectors has an air swirler associated with it to provide quick mixing and a small recirculation zone for burning. The multipoint fuel injection provides quick, uniform mixing and the small multiburning zones provide for reduced burning residence time, resulting in low NOx formation. An integrated-module approach was used for the construction where chemically etched laminates, diffusion bonded together, combine the fuel injectors, air swirlers, and fuel manifold into a single element. The multipoint concept combustor was demonstrated in a 15 sector test. The configuration tested had 36

Effect of advanced injection timing on the performance of natural gas ...

Indian Academy of Sciences (India)

Recent interest has centred on the use of natural gas in a diesel engine. Natural gas ... temperatures. Fuel was fed to the injector pump under gravity and the volumetric flow rate .... produce very erratic behaviour of the engine. The test results ...

The Natural Gas Vehicle Challenge 1992: Exhaust emissions testing and results

Science.gov (United States)

Rimkus, W. A.; Larsen, R. P.; Zammit, M. G.; Davies, J. G.; Salmon, G. S.; Bruetsch, R. I.

The Natural Gas Vehicle (NGV) Challenge '92, was organized by Argonne National Laboratory. The main sponsors were the U.S. Department of Energy the Energy, Mines, and Resources -- Canada, and the Society of Automotive Engineers. It resulted in 20 varied approaches to the conversion of a gasoline-fueled, spark-ignited, internal combustion engine to dedicated natural gas use. Starting with a GMC Sierra 2500 pickup truck donated by General Motors, teams of college and university student engineers worked to optimize Chevrolet V-8 engines operating on natural gas for improved emissions, fuel economy, performance, and advanced design features. This paper focuses on the results of the emission event, and compares engine mechanical configurations, engine management systems, catalyst configurations and locations, and approaches to fuel control and the relationship of these parameters to engine-out and tailpipe emissions of regulated exhaust constituents. Nine of the student modified trucks passed the current levels of exhaust emission standards, and some exceeded the strictest future emissions standards envisioned by the U.S. Environmental Protection Agency. Factors contributing to good emissions control using natural gas are summarized, and observations concerning necessary components of a successful emissions control strategy are presented.

Experimental validation of a combustion kinetics based multi-zone model for natural gas-diesel RCCI engines

NARCIS (Netherlands)

Mikulski, M.; Bekdemir, C.; Willems, F.P.T.

2016-01-01

This paper presents the validation results of TNO's combustion model designed to support RCCI control development. In-depth validation was performed on a multi-cylinder heavy-duty engine operating in RCCI mode on natural gas and diesel fuel. It was shown that the adopted approach is able to

Assessing and mitigating risks of engineering programs with lean management techniques

DEFF Research Database (Denmark)

Fritz, A.; Oehmen, Josef; Rebentisch, E.

2014-01-01

for a specific program are identified and how the effort for implementation of these lean best practices is estimated. Large-scale engineering programs have as results usually complex technical products or systems such as airplanes, satellites (GPS) or software programs, immense infrastructure efforts like...

Thermodynamic characteristics of a low concentration methane catalytic combustion gas turbine

International Nuclear Information System (INIS)

Yin, Juan; Su, Shi; Yu, Xin Xiang; Weng, Yiwu

2010-01-01

Low concentration methane, emitted from coal mines, landfill, animal waste, etc. into the atmosphere, is not only a greenhouse gas, but also a waste energy source if not utilised. Methane is 23 times more potent than CO 2 in terms of trapping heat in the atmosphere over a timeframe of 100 years. This paper studies a novel lean burn catalytic combustion gas turbine, which can be powered with about 1% methane (volume) in air. When this technology is successfully developed, it can be used not only to mitigate the methane for greenhouse gas reduction, but also to utilise such methane as a clean energy source. This paper presents our study results on the thermodynamic characteristics of this new lean burn catalytic combustion gas turbine system by conducting thermal performance analysis of the turbine cycle. The thermodynamic data including thermal efficiencies and exergy loss of main components of the turbine system are presented under different pressure ratios, turbine inlet temperatures and methane concentrations.

Technical and Feasibility Analysis of Gasoline and Natural Gas Fuelled Vehicles

Directory of Open Access Journals (Sweden)

Charalambos Chasos

2014-03-01

Full Text Available There is recent interest for the utilisation of natural gas for empowering the internal combustion engines (ICE of vehicles. The production of novel natural gas ICE for vehicles, as well as the conversion of existing gasoline fuelled ICE of vehicles to natural gas fuelled ICE are new technologies which require to be analysed and assessed. The objective of the present study is to examine the adaptation of natural gas as vehicle fuel and carry out a technical analysis and an economical feasibility analysis of the two types of ICE vehicles, namely gasoline and natural gas fuelled vehicles. The technical model uses the physical properties of the two fuels and the performance factors of internal combustion engines including brake thermal efficiency. The resulting exhaust gas emissions are also estimated by the technical model using combustion calculations which provide the expected levels of exhaust gas emissions. Based on the analysis with the technical model, comparisons of the two types of engines are performed. Furthermore, the estimated performance characteristics of the two types of engines, along with local statistical data on annual fuel imports and annual fuel consumption for transportation and data on the vehicles fleet for the case study of Cyprus are used as input in the economical model. For the base year 2013, data of natural gas price is also used in the economical model. The economical model estimates the capital cost, the carbon dioxide emissions avoidance of fines, the net present value and the internal rate of return of the investment of large scale adaptation of natural gas fuelled vehicles for the case study. From the results and comparisons, conclusions are drawn and recommendations are provided for the adaptation of natural gas vehicles which can provide improved performance with reduced pollutant emissions.

Environmental benefits of natural gas for buses

International Nuclear Information System (INIS)

Rabl, A.

2002-01-01

This paper presents a life cycle assessment comparing diesel buses with buses fueled by natural gas. The data for the emission of pollutants are based on the MEET Project of the European Commission (EC), supplemented by data measured for diesel and gas buses in Paris. The benefits of the gas fueled bus are then quantified using the damage cost estimates of the ExternE Project of the EC. A diesel bus with emissions equal to Standard EURO2 of the EC is compared with the same bus equipped with a natural gas engine, for use in Paris and in Toulouse. The damage cost of a diesel bus is significant, in the range of 0.4-1.3 euro/km. Natural gas allows an appreciable reduction of the emissions, lowering the damage cost by a factor of about 2.5 (Toulouse) to 5.5 (Paris). An approximate rule is provided for transferring the results to other cities. A sensitivity analysis is carried out to evaluate the effect of the evolution of the emissions standard towards EURO3, 4 and 5, as well as the effect of uncertainties. Finally a comparison is presented between a EURO2 diesel bus with particle filter, and a gas fueled bus with the MPI engine of IVECO, a more advanced and cleaner technology. With this engine the damage costs of the gas fueled bus are about 3-5 times lower than those of the diesel with particle filter, even though the latter has already very low emissions.(author)

The world's first supply ship powered by natural gas

International Nuclear Information System (INIS)

2003-01-01

The article describes the newly developed natural gas powered supply ship ''Viking Energy'', which reduces the emission of NOx by 200 tonnes per year. The shipping company has for many years been working on the developing of environmentally friendly ships with less fuel consumption. The gas is stored in liquid form at a temperature of 160 o C. The engines can run on gas or diesel as needed. These dual-fuel engines offers great flexibility, which is very desirable since liquid natural gas is not widely available along the coast. This type of engine has been used in power stations and on offshore platforms, but not in ships. The operating conditions are quite different for ships than for power stations. So far, both investment and operating costs are higher than for conventional ships

Overview of use of natural gas on heavy duty vehicles in Brazil; Panorama da utilizacao do gas natural veicular em veiculos pesados no Brasil

Energy Technology Data Exchange (ETDEWEB)

Machado, Guilherme Bastos; Melo, Tadeu Cavalcante Cordeiro de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Area de Desempenho de Produtos em Motores; Lastres, Luiz Fernando Martins [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Lubrificantes e Produtos Especiais

2004-07-01

The use of vehicular natural gas (VNG) was initiated in Brazil in he 80's seeking the replacement of diesel in heavy vehicles due to the oil crisis. In this season PETROBRAS participated, along with other companies, in the development of conversion technologies for replacement part of the diesel by natural gas through systems known as diesel-gas. Were made works to development bank of tests of engines and field tests on some bus companies, verifying if there are technical and economic viability of such conversion. Due to factors such as small mesh distribution of natural gas in Brazil, lack of infrastructure of technical support suitable for conversions and lack of culture in the use of natural gas, the program not progressed and experience was interrupted. Other experiments were conducted in Brazil with the use of engines dedicated to natural gas (Otto cycle) developed and manufactured in the country for use in urban buses. Currently there is a scenario favorable to the return of use of natural gas in weighed vehicles by the following factors: 1) increase the mesh distribution of VNG due to the high growth of the fleet light vehicles to VNG in the country, solving part of the problems of logistics; 2) pressure from environmental agencies by values of emissions of particles and gases ever less pollutants in urban centers; 3) excess supply of natural gas in the domestic market due to new discoveries in Brazil, contracts for the import of natural gas signed with Bolivia and low demand for current industrial consumption of gas; 4) need to replace the import of diesel, which weighs in trade of the country. This paper will be presented some experiences with the technology of diesel-gas and the engine dedicated the VNG in weighed vehicles in Brazil. Also some recommendations will be made to increase and spread the use of these technologies, aiming to increase the replacement of diesel by vehicular natural gas in weighed vehicles. (author)

A Comparison of Three Second-generation Swirl-Venturi Lean Direct Injection Combustor Concepts

Science.gov (United States)

Tacina, Kathleen M.; Podboy, Derek P.; He, Zhuohui Joe; Lee, Phil; Dam, Bidhan; Mongia, Hukam

2016-01-01

Three variations of a low emissions aircraft gas turbine engine combustion concept were developed and tested. The concept is a second generation swirl-venturi lean direct injection (SV-LDI) concept. LDI is a lean-burn combustion concept in which the fuel is injected directly into the flame zone. All three variations were based on the baseline 9- point SV-LDI configuration reported previously. The three second generation SV-LDI variations are called the 5-recess configuration, the flat dome configuration, and the 9- recess configuration. These three configurations were tested in a NASA Glenn Research Center medium pressure flametube. All three second generation variations had better low power operability than the baseline 9-point configuration. All three configurations had low NO(sub x) emissions, with the 5-recess configuration generally having slightly lower NO(x) than the flat dome or 9-recess configurations. Due to the limitations of the flametube that prevented testing at pressures above 20 atm, correlation equations were developed for the at dome and 9-recess configurations so that the landing-takeoff NO(sub x) emissions could be estimated. The flat dome and 9-recess landing-takeoff NO(x) emissions are estimated to be 81-88% below the CAEP/6 standards, exceeding the project goal of 75% reduction.

Modification Design of Petrol Engine for Alternative Fueling using Compressed Natural Gas

Directory of Open Access Journals (Sweden)

Eliezer Uchechukwu Okeke

2013-04-01

Full Text Available This paper is on the modification design of petrol engine for alternative fuelling using Compressed Natural Gas (CNG. It provides an analytical background in the modification design process. A petrol engine Honda CR-V 2.0 auto which has a compression ratio of 9.8 was selected as case study. In order for this petrol engine to run on CNG, its compression had to be increased. An optimal compression ratio of 11.97 was computed using the standard temperature-specific volume relationship for an isentropic compression process. This computation of compression ratio is based on an inlet air temperature of 30oC (representative of tropical ambient condition and pre-combustion temperature of 540oC (corresponding to the auto-ignition temperature of CNG. Using this value of compression ratio, a dimensional modification Quantity =1.803mm was obtained using simple geometric relationships. This value of 1.803mm is needed to increase the length of the connecting rod, the compression height of the piston or reducing the sealing plate’s thickness. After the modification process, a CNG engine of air standard efficiency 62.7% (this represents a 4.67% increase over the petrol engine, capable of a maximum power of 83.6kW at 6500rpm, was obtained.

Development and test of a new catalytic converter for natural gas ...

Indian Academy of Sciences (India)

catalytic converter and a new natural gas engine such as compressed natural gas. (CNG) direct ..... bility to store oxygen from random gas flow within the substrate in comparison to flow through ..... and behaviour in the water–gas shift reaction.

Wood and natural gas as fuels for tunnel kilns in the clay-product industry; Serragem e gas natural como fontes energeticas em fornos tuneis na industria ceramica vermelha

Energy Technology Data Exchange (ETDEWEB)

Santos, Gabriel M. dos; Bazzo, Edson; Nicolau, Vicente de P.; Oliveira, Amir A.M. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mails: mann@emc.ufsc.br; ebazzo@emc.ufsc.br; vicente@lmpt.ufsc.br; amirol@emc.ufsc.br

2000-07-01

The clay-product industry is responsible to large part of the thermal energy consumption, especially on drying and burning process. In spite of the success obtained with the burning of wood like principal fuel for tunnel kilns, the clay-product industries of Santa Catarina have looked for alternatives to substitute it. The interest appears especially due to imminent shortage of the wood on the market and due to possibility of use natural gas as a good and environmentally favorable alternative to reduce the energy specific consumption of the kilns, to increase the production and to improve the quality of the ceramic products. Nowadays, the natural gas is more expensive when compared with the wood. However, we believe that additional studies can place this fuel as a viable alternative to the clay-product industries. (author)

Evaluation and development of direct burning natural gas industrial equipment in the food sector; Avaliacao e desenvolvimento de equipamentos industriais de queima direta de gas natural no setor de alimentos

Energy Technology Data Exchange (ETDEWEB)

Schwob, Marcelo; Morales, Maria Elizabeth; Henriques, Mauricio; Guimaraes, Marcio; Tapia, Roberto; Rodrigues, Joaquim; Faccion, Alexandre [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil)

2004-07-01

The aim of this study, focused in the food sector, is evaluate and develop technologies used in equipment of direct burning natural gas, as ovens and driers of common use in the toasting coffee, noodles and biscuits industries. We have developed an archetype of oven for baking, seeking to incorporate new technological concepts but showing operational conditions of great attractiveness for the users of this kind of equipment. Above all, aiming the optimization of the technologies to improve the energy efficiency, to reduce costs and to increase the operational security. Thus, a survey of the thermal equipment in the mentioned industrial sector was made, followed of an evaluation of the technical possibilities of its incorporation in that sector, adaptations and the modifications of engineering projects, identifying the possibilities of productivity increase, improvement of quality and greater competitiveness, as well as the reduction of atmospheric emissions. So, It has been proposed solutions as the decentralized use of the thermal energy, recovery of heat of exhaustion gases, optimization of the thermal insulation, reduction of thermal inertia and the automatization of the control of the combustion in ovens and/or driers of the mentioned sectors. The main results of this study are: the possibility of reduction of, 32 to 37% in the consumption of thermal energy in the ovens of biscuit production, of 12 to 15% in the toasting of coffee and 20 to 30% in the processes of noodles production. Saving of around 25% would be expected in the small bearing ovens for baking. (author)

Device for the catalytic after-burning of exhaust gases in the exhaust gas system of an internal-combustion engine

Energy Technology Data Exchange (ETDEWEB)

Lange, K

1975-06-19

The invention deals with a device which protects the catalyst for the after-burning of exhaust gases against damage by high temperatures. When the catalyst temperature reaches a certain limiting value, a throttle is activated by an electrical control device influenced by a temperature sensor via a servomotor. The throttle valve opens a by-pass for the exhaust gases which had previously flowed through the system for catalytic after-burning. In order to prevent the throttle from rusting due to its rare use, it is regularly put into use after switching off the ignition of the internal-combustion engine by the still briefly present oil pressure in the engine via an oil pressure switch and the mentioned control device.

Numerical Investigation of the Low-Caloric Gas Burning Process in a Bottom Burner

Directory of Open Access Journals (Sweden)

Redko A.

2017-08-01

Full Text Available The use of low-grade gases in the fuel and energy balance of enterprises makes it possible to increase the energy efficiency of technological processes. The volumes of low-grade gases (blast furnace and coke oven gases, synthesis gas of coal gasification processes, biogas, coal gas, etc. that are utilized more significant in technological processes but their calorific value are low. At the same time artificial gases contain ballast gaseous (СО2, H2O and mechanical impurities that are harmful gas impurities. Their use requires technological preparation. Thus coal methane is characterized of high humidity, coal dust and drip moisture, variable composition. Thus was effective burning of coal methane it is required the development of constructive and regime measures that ensure a stable and complete burning of gaseous fuels. In this article it is presented the results of computer simulation of a stationary turbulent diffusion flame in a restricted space in the process of burning natural gas and coal methane in a bottom burner. The calculation results contain the fields of gear, temperature, concentration of CH4‚ CO‚ H2O‚ CO2 and nitrogen oxides. The structural elements of the flame (recirculation zone, hot "dome", mixing layer and far trace are determined. It has been established that complete combustion of coal methane in a modified bottom burner is ensured and the numerical values of nitrogen oxide concentrations in the flame are consistent with the literature data.

Performance and emissions of a dual-fuel pilot diesel ignition engine operating on various premixed fuels

International Nuclear Information System (INIS)

Yousefi, Amin; Birouk, Madjid; Lawler, Benjamin; Gharehghani, Ayatallah

2015-01-01

Highlights: • Natural gas/diesel, methanol/diesel, and hydrogen/diesel cases were investigated. • For leaner mixtures, the hydrogen/diesel case has the highest IMEP and ITE. • The methanol/diesel case has the maximum IMEP and ITE for richer mixtures. • Hydrogen/diesel case experiences soot and CO free combustion at rich regions. - Abstract: A multi-dimensional computational fluid dynamics (CFD) model coupled with chemical kinetics mechanisms was applied to investigate the effect of various premixed fuels and equivalence ratios on the combustion, performance, and emissions characteristics of a dual-fuel indirect injection (IDI) pilot diesel ignition engine. The diesel fuel is supplied via indirect injection into the cylinder prior to the end of the compression stroke. Various premixed fuels were inducted into the engine through the intake manifold. The results showed that the dual-fuel case using hydrogen/diesel has a steeper pressure rise rate, higher peak heat release rate (PHRR), more advanced ignition timing, and shorter ignition delay compared to the natural gas/diesel and methanol/diesel dual-fuel cases. For leaner mixtures (Φ_P 0.32). For instance, with an equivalence ratio of 0.35, the ITE is 56.24% and 60.85% for hydrogen/diesel and methanol/diesel dual-fuel cases, respectively. For an equivalence ratio of 0.15, the natural gas/diesel simulation exhibits partial burn combustion and thus results in a negative IMEP. At equivalence ratios of 0.15, 0.2, and 0.25, the methanol/diesel case experiences misfiring phenomenon which consequently deteriorates the engine performance considerably. As for the engine-out emissions, the hydrogen/diesel results display carbon monoxide (CO) free combustion relative to natural gas/diesel and methanol/diesel engines; however, considerable amount of nitrogen oxides (NO_x) emissions are produced at an equivalence ratio of 0.35 which exceeds the Euro 6 NO_x limit. Due to the larger area exposed to high temperature regions

NOx emission control in SI engine by adding argon inert gas to intake mixture

International Nuclear Information System (INIS)

Moneib, Hany A.; Abdelaal, Mohsen; Selim, Mohamed Y.E.; Abdallah, Osama A.

2009-01-01

The Argon inert gas is used to dilute the intake air of a spark ignition engine to decrease nitrogen oxides and improve the performance of the engine. A research engine Ricardo E6 with variable compression was used in the present work. A special test rig has been designed and built to admit the gas to the intake air of the engine for up to 15% of the intake air. The system could admit the inert gas, oxygen and nitrogen gases at preset amounts. The variables studied included the engine speed, Argon to inlet air ratio, and air to fuel ratio. The results presented here included the combustion pressure, temperature, burned mass fraction, heat release rate, brake power, thermal efficiency, volumetric efficiency, exhaust temperature, brake specific fuel consumption and emissions of CO, CO 2 , NO and O 2 . It was found that the addition of Argon gas to the intake air of the gasoline engine causes the nitrogen oxide to reduce effectively and also it caused the brake power and thermal efficiency of the engine to increase. Mathematical program has been used to obtain the mixture properties and the heat release when the Argon gas is used.

Experimental and theoretical analysis of the combustion process at low loads of a diesel natural gas dual-fuel engine

International Nuclear Information System (INIS)

Li, Weifeng; Liu, Zhongchang; Wang, Zhongshu

2016-01-01

To construct an effective method to analyze the combustion process of dual fuel engines at low loads, effects of combustion boundaries on the combustion process of an electronically controlled diesel natural gas dual-fuel engine at low loads were investigated. Three typical combustion modes, including h, m and n, appeared under different combustion boundaries. In addition, the time-sequenced characteristic and the heat release rate-imbalanced characteristic were found in the dual fuel engine combustion process. To quantify these characteristics, two quantitative indicators, including the TSC (time-sequenced coefficient) and the HBC (HRR-balanced coefficient) were defined. The results show that increasing TSC and HBC can decrease HC (hydrocarbon) emissions and improve the BTE (brake thermal efficiency) significantly. The engine with the n combustion mode can obtain the highest BTE and the lowest HC emissions, followed by m, and then h. However, the combustion process of the engine will deteriorate sharply if boundary conditions are not strictly controlled in the n combustion mode. Based on the n combustion mode, advancing the start of diesel injection significantly, using large EGR (exhaust gas recirculation) rate and appropriately intake throttling can effectively reduce HC emissions and improve the BTE of dual fuel engines at low loads with relatively high natural gas PES (percentage energy substitution). - Highlights: • We reported three typical combustion modes of a dual-fuel engine at low loads. • Time-sequenced characteristic was put forward and qualified. • HRR-imbalanced characteristic was put forward and qualified. • Three combustion modes appeared as equivalence ratio/diesel injection timing varied. • The engine performance varied significantly with different combustion mode.

Five-year epidemiology of liquefied petroleum gas-related burns.

Science.gov (United States)

Jin, Ronghua; Wu, Pan; Ho, Jon Kee; Wang, Xingang; Han, Chunmao

2018-02-01

The incidence of liquefied petroleum gas (LPG)-related burns has increased over recent years, and it has become a serious public health issue in developing countries such as India and Turkey. This paper aims to investigate the epidemiological characteristics of LPG-related burns to provide assistance and suggestions for planning prevention strategies. A 5-year retrospective study was conducted in patients with LPG-related burns admitted to the Department of Burns & Wound Care Center, Second Affiliated Hospital of Zhejiang University, College of Medicine, between 1st January 2011 and 31st December 2015. Information obtained for each patient included age, gender, education status, occupation, medical insurance, average hospital cost, length of hospital stay, monthly distribution of incidence, place of burns, mechanism of burns, extent of burns, site of burns, accompanying injuries, and treatment outcomes. For the first 4 years (2011-2014), the yearly incidence of LPG-related burns was at approximately 10% of all burns; however, in the fifth year (2015) alone, there was a surge to 26.94%. A total of 1337 burn patients were admitted during this period. Of these, 195 patients were admitted because of 169 LPG-related accidents; there were 11 accidents involving more than one victim. LPG-related burns occurred most frequently in patients aged 21-60 years (73.85%). The majority of injuries occurred from May to August (56.41%), and the most common place was home (83.08%, 162 patients). Gas leak (81.03%) was the main cause of LPG-related burns, followed by inappropriate operation (7.69%) and cooking negligence (2.05%). The mean burn area was 31.32±25.40% of TBSA. The most common sites of burns were the upper extremities (37.47%), followed by the head/face and neck (24.80%) and lower extremities (19.95%). The most common accompanying injuries included inhalation injury (23.59%), shock (8.71%), and external injury (7.18%). The average hospital stay was 22.90±19.47days (range

The prospects of natural gas vehicles in France and Europe

International Nuclear Information System (INIS)

Nicolle, J.M.

2009-01-01

Given the availability and environmental advantages of natural gas, several countries soon felt that natural gas vehicles (NGVs) were a logical way to respond to transportation needs while meeting up to the standards of sustainable development. Natural gas is now a genuine alternative to petroleum products, and NGVs are capable of using the current engine technology. (author)

Comportamento de um motor de ignição por compressão trabalhando com óleo Diesel e gás natural A dual fuel compression ignition engine performance, running with Diesel fuel and natural gas

Directory of Open Access Journals (Sweden)

José F. Schlosser

2004-12-01

Full Text Available A previsível escassez de petróleo aliada a uma consciência ecológica está levando pesquisadores a procurar novas fontes de energia e processos de combustão mais eficientes e menos poluentes. Entre os combustíveis menos poluentes está o gás natural, cujo consumo aumenta ano a ano. Os motores de combustão interna são transformadores de energia que têm baixa eficiência de conversão. Este trabalho avaliou um motor Diesel, bicombustível, movido a Diesel e gás natural. Nesse motor, a energia provém, basicamente, da combustão do gás natural. O Diesel tem a função de produzir o início da combustão do gás, que é o combustível principal. Assim, haverá uma substituição parcial de óleo Diesel por gás natural, aumentando o rendimento da combustão. Inicialmente, foi feito um ensaio-testemunha, somente com óleo Diesel e após foram feitos ensaios, com três repetições, para variadas proporções de óleo Diesel, gás natural e ângulos de avanço da injeção. O melhor desempenho foi obtido para 22% de óleo Diesel em relação ao máximo débito da bomba injetora e 13 L min-1 de gás natural com ângulo de avanço de injeção original (21º. Nesse caso, a potência média aumentou 14%, e o consumo específico (medido em valores monetários diminuiu 46% em relação ao ensaio-testemunha.The foresight of a petroleum shortage and an ecological conscience is moving scientists to look for new sources of energy and to develop more efficient combustion processes and reduced emissions. Natural gas is a reduced emission fuel, whose consumption increases every year. The present work evaluates a dual fuel compression ignition engine. The major portion of the fuel burned is natural gas. The Diesel fuel acts as combustion starter, which ignites under the compression heat. Diesel fuel is used only as an ignition source. The partial substitution of Diesel fuel by natural gas increases the combustion efficiency and achieves significant

A new technology to overcome the limits of HCCI engine through fuel modification

International Nuclear Information System (INIS)

Bahng, GunWoong; Jang, Dongsoon; Kim, Youngtae; Shin, Misoo

2016-01-01

Highlights: • Problems of HCCI engine can be overcome by adopting fuel modification. • Gasoline vapor with HHO gas showed drastic improvement of fuel efficiency. • Performance of single cylinder engine shows fuel efficiency more than double. - Abstract: The energy efficiency of internal combustion engine reached to about 30% only recently. To increase the efficiency, homogeneous charge compression ignition (HCCI) has been proposed, however, there is no available commercial engine yet. The main problem lies in the delayed heating rate in spite of fast reaction of homogeneous charged state of HCCI with excess air. To overcome this difficulty, a modification of fuel by vaporization of liquid gasoline with water electrolysis gas and air was adopted in order to warrant the fast and high temperature rise. Experiments were carried out with single cylinder engines supplied from the four different manufacturers. Experimental results show that fuel consumption was decreased by more than 50% compared to the case of supplying liquid fuel. It is believed it was due to the combined effects of the high and fast heating potential of water electrolysis gas together with the efficient turbulence mixing effect of vaporized fuel with excess air. By this method, the drawbacks caused by lean burn in the HCCI engine such as small power range can be overcome.

Experimental study of hydrogen as a fuel additive in internal combustion engines

Energy Technology Data Exchange (ETDEWEB)

Saanum, Inge

2008-07-01

. % hydrogen to the methane, but 5 vol. % hydrogen also resulted in a noticeable increase. The flame structure was also influenced by the hydrogen addition as the flame front had a higher tendency to become wrinkled or cellular. The effect is believed to mainly be caused by a reduction in the effective Lewis number of the mixture. In the gas engine experiments, the effect of adding 25 vol. % hydrogen to natural gas was investigated when the engine was run on lean air/fuel mixtures and on stoichiometric mixtures with exhaust gas recirculation. The hydrogen addition was found to extend the lean limit of stable combustion and hence caused lower NO{sub x} emissions. The brake thermal efficiency increased with the hydrogen addition, both for the fuel lean and the stoichiometric mixtures with exhaust gas recirculation. This is mainly because of shorter combustion durations when the hydrogen mixture was used, leading to thermodynamically improved cycles. Two types of experiments were performed in compression ignition engines. First, homogenous charge compression ignition (HCCI) experiments were performed in a single cylinder engine fueled with natural gas and diesel oil. As HCCI engines have high thermal efficiency and low NO{sub x} and PM emissions it may be more favorable to use natural gas in HCCI engines than in spark ignition engines. The mixture of natural gas, diesel oil and air was partly premixed before combustion. The natural gas/diesel ratio was used to control the ignition timing as the fuels have very different ignition properties. The natural gas was also replaced by a 20 vol. % hydrogen/natural gas mixture to study the effect of hydrogen on the ignition and combustion process. Also, rape seed methyl ester (RME) was tested instead of the diesel oil. The combustion phasing was found to mainly be controlled by the amount of liquid fuel injected. The last experiments with compression ignition were performed by using a standard Scania diesel engine where the possibilities

Energy equivalence factor in gasoline to compressed vehicle natural gas substitution

International Nuclear Information System (INIS)

Agudelo Santamaria, John R; Amell Arrieta, Andres A

1992-01-01

In this paper, the authors show a model based in a vehicle energy balance used to obtain the ratio of energy equivalence of natural gas and petrol used as fuels in the vehicle. The model includes the engine, transmission and natural gas cylinders effects. The model has been applied to different colombian natural gases, it shows that Guajira natural gas has 14,5% lower ratio than Cusiana natural gas and 5,6% lower ratio than Apiay natural gas, these results shows a need in the study of colombian natural gases interchangeability

Has the natural gas fueled bus any future?

International Nuclear Information System (INIS)

Riikonen, A.

2001-01-01

Helsinki City Transport has decided to operate public transport in the center of the city with tramways and gas-fuelled busses. The decision is that there will be about 100 natural gas fueled busses in Helsinki by the year 2003. European exhaust gas emission (NO x and particulates) regulations have tightened strongly during the past few years. The regulations have forced to search for new fuels by the side of development of diesel engines. Alcohols, in spite of favourable fuel properties, are too expensive, so the use of them needs large subsidies for transportation sector. Gaseous fuels, both LPG and natural gas are suitable fuels for Otto cycle-cycle engines. After the previous oil crisis the interest in gas-fuelled engines has steadily decreased, but at present it is increasing again because of the objectives to decrease emissions of heavy vehicles at the level of gasoline-fuelled vehicles, equipped with three-way catalyst. From the point of view of emissions natural gas and LPG are seen as equivalent alternatives. The price of LPG varies on the basis of demand and on the basis of the prices of other oil products. Refuelling of a vehicle and storage of LPG in liquid form in the tank of the vehicle is easier than refuelling and fuel storage of natural gas. Investments to refuelling equipment of LPG are only 20% of those of the natural gas refuelling systems. The problem of natural gas is also the fact that is not easy to carry in the vehicle. Even if natural gas is compressed to pressure of 200 bars, it requires six times larger tanks if the refuelling intervals are the same. Liquefaction of natural gas reduces the volume significantly, but this is complicated and hence expensive. The tank of a vehicle should be vacuum insulated because the temperature of the LNG is about 160 deg C. Tank volume of LPG is only about twice that of diesel oil. Safety of natural gas is high, because it is lighter than the air, nearly a half of the density of the air. Octane ratings

Compressed natural gas for vehicles and how we can develop and meet the market

International Nuclear Information System (INIS)

Pinkerton, W.E.

1992-01-01

This paper reports that state and federal legislation have mandated the use of clean burning fuels. Clean fuels include: compressed natural gas (CNG), ethanol, methanol, liquefied petroleum gas (LPG), electricity, and reformulated gasoline. The Clean Air Amendments 1990 have created support for the rapid utilization of the compressed natural gas (CNG). Responsively, diverse occupations related to this industry are emerging. A coordinated infrastructure is vital to the successful promotion of clean fuels and synchronized endorsement of the law

Emission characterization and evaluation of natural gas-fueled cogeneration microturbines and internal combustion engines

International Nuclear Information System (INIS)

Canova, Aldo; Chicco, Gianfranco; Genon, Giuseppe; Mancarella, Pierluigi

2008-01-01

The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO 2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NO x , and thus could worsen the local air quality. This paper provides an overview on the characterization of the emissions from small-scale natural gas-fueled cogeneration systems, with specific reference to the DG technologies nowadays most available in the market, namely, microturbines and internal combustion engines. The corresponding local and global environmental impacts are evaluated by using the emission balance approach. A numerical case study with two representative machines highlights their different emission characteristics, also considering the partial-load emission performance

Natural gas

Energy Technology Data Exchange (ETDEWEB)

Fraser, J W

1967-08-01

This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

LEAN-GREEN MANUFACTURING: COLLABORATIVE CONTENT AND LANGUAGE INTEGRATED LEARNING IN HIGHER EDUCATION AND ENGINEERING COURSES

Directory of Open Access Journals (Sweden)

MARCELO RUDOLFO CALVETE GASPAR

2017-09-01

Full Text Available Lean and Green manufacturing processes aim at achieving lower material and labour costs, while reducing impacts on the environment, and promoting sustainability as a whole. This paper reports on a pilot experiment with higher education and engineering students, exploring the full potential of a collaborative approach on courses integrating the Portuguese Polytechnic of Castelo Branco engineering studies curricula, while simultaneously improving their proficiency in English. Content and Language Integrated Learning (CLIL has become a key area of curricular innovation since it is known for improving both language and content teacher and student motivation. In this context, instructional design for CLIL entailed tandem work of content (engineering and language (English teacher to design learning sequences and strategies. This allowed students to improve not only their language skills in English but also their knowledge in the specific engineering domain content on green and lean manufacturing processes.

Keynote address: The future of Asian natural gas--The Petronas perspective

International Nuclear Information System (INIS)

Abidin, T.S.A.Z.

1991-01-01

In the last several years, the Asian Pacific Region has been experiencing a high rate of economic growth. The prospects for the future would appear to be no less bullish. There is a heightened demand for energy and a greater sense of urgency to change to a cleaner burning fuel. These and other factors indicate a significant increase in demand for natural gas. Fortunately, Malaysian reserves are adequate to meet this demand. PETRONAS is vigorously pursuing actions that will expand its supply capabilities. This expansion along with long-term agreements on pricing and sales with gas purchasers will assure the future role of Asian natural gas in domestic and export markets

A Case Study Improvement of a Testing Process by Combining Lean Management, Industrial Engineering and Automation Methods

Directory of Open Access Journals (Sweden)

Simon Withers

2013-07-01

Full Text Available Increasingly competitive market environments have forced not only large manufacturing, but also smalland-medium size enterprises (SME to look for means to improve their operations in order to increase competitive strength. This paper presents an adaptation and adoption by a UK SME engineering service organisation, of lean management, industrial engineering, and automation metods developed within larger organisations. This SME sought to improve the overall performance of one of its core testing processes. An exploratory analysis, based on the lean management concept of “value added” and work measurement technique “time study”, was developed and carried out in order to understand the current performance of a testing process for gas turbine fuel flow dividers. A design for the automation of some operations of the testing process was followed as an approach to reduce non-value added activities, and improve the overall efficiency of the testing process. The overall testing time was reduced from 12.41 to 7.93 hours (36.09 percent while the man hours and non-value added time were also reduced from 23.91 to 12.94 hours (45.87 percent and from 11.08 to 6.69 (39.67 percent hours respectively. This resulted in an increase in process efficiency in terms of man hours from 51.91 to 61.28 percent. The contribution of this paper resides in presenting a case study that can be used as a guiding reference for managers and engineers to undertake improvement projects, in their organisations, similar to the one presented in this paper.

Investigation of fuel lean reburning process in a 1.5 MW boiler

International Nuclear Information System (INIS)

Kim, Hak Young; Baek, Seung Wook; Kim, Se Won

2012-01-01

Highlights: → We examine a detailed study of fuel lean reburning process in a 1.5 MW gas-fired boiler. → Experimental and numerical researches are conducted. → We investigate change in the level of NO X and CO emission. → The recirculation flow is important in the fuel lean reburning process. -- Abstract: This paper examines a detailed study of fuel lean reburning process applied to a 1.5 MW gas-fired boiler. Experimental and numerical studies were carried out to investigate the effect of the fuel lean reburning process on the NO X reduction and CO emission. Natural gas (CH 4 ) was used as the reburn as well as the main fuel. The amount of the reburn fuel, injection location and thermal load of boiler were considered as experimental parameters. The flue gas data revealed that the fuel lean reburning process led to NO X reduction up to 43%, while CO emission was limited to less than 30 ppm for the 100% thermal load condition. The commercial computational fluid dynamics code FLUENT 6.3, which included turbulence, chemical reaction, radiation and NO modeling, was used to predict the fluid flow and heat transfer characteristics under various operational conditions in the boiler. Subsequently, predicted results were validated with available measured data such as gas temperature distributions and local mean NO X concentrations. The detailed numerical results showed that the recirculation flow developed inside the boiler was found to play an important role in improving the effectiveness of fuel lean reburning process.

Natural gas and renewable methane for powertrains future strategies for a climate-neutral mobility

CERN Document Server

2016-01-01

This book focuses on natural gas and synthetic methane as contemporary and future energy sources. Following a historical overview, physical and chemical properties, occurrence, extraction, transportation and storage of natural gas are discussed. Sustainable production of natural gas and methane as well as production and storage of synthetic methane are scrutinized next. A substantial part of the book addresses construction of vehicles for natural and synthetic methane as well as large engines for industrial and maritime use. The last chapters present some perspectives on further uses of renewable liquid fuels as well as natural gas for industrial engines and gas power plants.

Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

Science.gov (United States)

Sherlock, T. P.

1982-01-01

Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

Natural and synthetic polymers for wounds and burns dressing.

Science.gov (United States)

Mogoşanu, George Dan; Grumezescu, Alexandru Mihai

2014-03-25

In the last years, health care professionals faced with an increasing number of patients suffering from wounds and burns difficult to treat and heal. During the wound healing process, the dressing protects the injury and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan, heparin, chondroitin), proteoglycans and proteins (collagen, gelatin, fibrin, keratin, silk fibroin, eggshell membrane) are extensively used in wounds and burns management. Obtained by electrospinning technique, some synthetic polymers like biomimetic extracellular matrix micro/nanoscale fibers based on polyglycolic acid, polylactic acid, polyacrylic acid, poly-ɛ-caprolactone, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, exhibit in vivo and in vitro wound healing properties and enhance re-epithelialization. They provide an optimal microenvironment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good mechanical properties. Thus, synthetic polymers are used also in regenerative medicine for cartilage, bone, vascular, nerve and ligament repair and restoration. Biocompatible with fibroblasts and keratinocytes, tissue engineered skin is indicated for regeneration and remodeling of human epidermis and wound healing improving the treatment of severe skin defects or partial-thickness burn injuries. Copyright © 2013 Elsevier B.V. All rights reserved.

Mensuration of the propagation speed of mixed flames of Methane-air and gas natural, Guajira - air using the method of the angle of the cone

International Nuclear Information System (INIS)

Benjumea Hernandez, Pedro Nel; Higuita Bedoya Carlos Mario; Cordoba Perez, Camilo Andres

2004-01-01

In this work, the burning velocity of premixed laminar flames of methane-air and Guajira natural gas-air mixtures was measured by the cone's angle method using a cylindrical Bunsen burner. In the development of the experiments, a fuel concentration in the fuel-air mixture ranging from 9% -11% was taken. The maximum value of the burning velocity was obtained for mixtures a little bit richer than the stoichiometric case. For methane, this flame velocity was 44.1 cm/s and for the Guajira natural gas was 43.1 cm/s. From the results, it was possible to see that the Guajira natural gas inert content led to a burning velocity value lesser than the methane's, in spite of the Guajira natural gas having a higher heavy hydrocarbon content. Methane burning velocity values following similar trends to those reported by the literature were obtained. The systematic error found in the results is mainly a consequence of inaccuracies in the method used to measure the fuel-gas mixture velocity at the burner exit

The atomization and burning of biofuels in the combustion chambers of gas turbine engines

Science.gov (United States)

Maiorova, A. I.; Vasil'ev, A. Yu; Sviridenkov, A. A.; Chelebyan, O. G.

2017-11-01

The present work analyzes the effect of physical properties of liquid fuels with high viscosity (including biofuels) on the spray and burning characteristics. The study showed that the spray characteristics behind devices well atomized fuel oil, may significantly deteriorate when using biofuels, until the collapse of the fuel bubble. To avoid this phenomenon it is necessary to carry out the calculation of the fuel film form when designing the nozzles. As a result of this calculation boundary curves in the coordinates of the Reynolds number on fuel - the Laplace number are built, characterizing the transition from sheet breakup to spraying. It is shown that these curves are described by a power function with the same exponent for nozzles of various designs. The swirl of air surrounding the nozzle in the same direction, as the swirl of fuel film, can significantly improve the performance of atomization of highly viscous fuel. Moreover the value of the tangential air velocity has the determining influence on the film shape. For carrying out of hot tests in aviation combustor some embodiments of liquid fuels were proved and the most preferred one was chosen. Fire tests of combustion chamber compartment at conventional fuel has shown comprehensible characteristics, in particular wide side-altars of the stable combustion. The blended biofuel application makes worse combustion stability in comparison with kerosene. A number of measures was recommended to modernize the conventional combustors when using biofuels in gas turbine engines.

Role of natural gas in meeting an electric sector emissions reduction strategy and effects on greenhouse gas emissions

International Nuclear Information System (INIS)

Lenox, Carol; Kaplan, P. Ozge

2016-01-01

With advances in natural gas extraction technologies, there is an increase in the availability of domestic natural gas, and natural gas is gaining a larger share of use as a fuel in electricity production. At the power plant, natural gas is a cleaner burning fuel than coal, but uncertainties exist in the amount of methane leakage occurring upstream in the extraction and production of natural gas. At higher leakage levels, the additional methane emissions could offset the carbon dioxide emissions reduction benefit of switching from coal to natural gas. This analysis uses the MARKAL linear optimization model to compare the carbon emissions profiles and system-wide global warming potential of the U.S. energy system over a series of model runs in which the power sector is required to meet a specific carbon dioxide reduction target across a number of scenarios in which the availability of natural gas changes. Scenarios are run with carbon dioxide emissions and a range of upstream methane emission leakage rates from natural gas production along with upstream methane and carbon dioxide emissions associated with production of coal and oil. While the system carbon dioxide emissions are reduced in most scenarios, total carbon dioxide equivalent emissions show an increase in scenarios in which natural gas prices remain low and, simultaneously, methane emissions from natural gas production are higher. - Highlights: • MARKAL analysis of energy system GHG emissions reduction scenarios. • High methane leakage can eliminate the benefit that natural gas brings over coal. • A robust GHG reduction strategy takes into account upstream emissions for all fuels.

Low Pressure Storage of Natural Gas for Vehicular Applications

International Nuclear Information System (INIS)

Tim Burchell; Mike Rogers

2000-01-01

Natural gas is an attractive fuel for vehicles because it is a relatively clean-burning fuel compared with gasoline. Moreover, methane can be stored in the physically adsorbed state[at a pressure of 3.5 MPa (500 psi)] at energy densities comparable to methane compressed at 24.8 MPa (3600 psi). Here we report the development of natural gas storage monoliths[1]. The monolith manufacture and activation methods are reported along with pore structure characterization data. The storage capacities of these monoliths are measured gravimetrically at a pressure of 3.5 MPa (500 psi) and ambient temperature, and storage capacities of and gt;150 V/V have been demonstrated and are reported

The gas fireplace: a new burn hazard in the home.

Science.gov (United States)

Becker, L; Cartotto, R

1999-01-01

Gas fireplaces have become popular in recent years. This article presents the first reported case of a burn injury from contact with the glass front of a gas fireplace. An investigation of the surface temperature of the glass fronts of gas fireplaces was undertaken to clarify the risks posed by these units. Surface temperature measurements of the glass fronts of 3 common gas fireplace models were obtained using a thermocouple probe. Glass temperatures reached 200 degrees C within 6.5 minutes of ignition, climbing to 245 degrees C at 14 minutes after ignition. Glass temperature continued to rise beyond this point, but it could not be monitored because the adhesives securing the thermocouple probe melted. Glass temperatures of 50 degrees C were recorded at 30 minutes after the unit was shut off. The temperatures of the glass fronts of glass fireplaces are sufficient to cause cutaneous burns within seconds of contact both while the fireplace is in use and up to one half hour after it has been turned off. Current industry safety standards are not directed at the prevention of contact burns. We recommend that (1) mechanical guards be installed to create a barrier in front of the glass; (2) strict warning labels be applied to the units and ignition switches; and (3) burn prevention information be distributed with the owner's manual for these products.

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

Energy Technology Data Exchange (ETDEWEB)

Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

2005-12-01

This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray Characteristics

Science.gov (United States)

Tedder, Sarah A.; Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2015-01-01

Lean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 degrees is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.

Practical support for Lean Six Sigma software process definition using IEEE software engineering standards

CERN Document Server

Land, Susan K; Walz, John W

2012-01-01

Practical Support for Lean Six Sigma Software Process Definition: Using IEEE Software Engineering Standards addresses the task of meeting the specific documentation requirements in support of Lean Six Sigma. This book provides a set of templates supporting the documentation required for basic software project control and management and covers the integration of these templates for their entire product development life cycle. Find detailed documentation guidance in the form of organizational policy descriptions, integrated set of deployable document templates, artifacts required in suppo

US crude oil, natural gas, and natural gas liquids reserves

International Nuclear Information System (INIS)

1992-01-01

This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1991, as well as production volumes for the United States, and selected States and State subdivisions for the year 1991. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1991 is also presented

Obstacles to lean in healthcare: Mindsets and the nature of work

DEFF Research Database (Denmark)

Edwards, Kasper; Nielsen, Anders Paarup

2009-01-01

The ideas and principles from lean management are now widely being adopted within the health care sector. The interest in lean from managers and policy makers, however, appear to contrast the realized benefits. An analysis of cases reported in literature and three Danish healthcare cases show...... for example laboratory work, logistical issues for patient e.g. emergency room layout, billing processes, and logistics of medical supplies. At first glance an explanation could be found in the conservative nature of the medical community which needs substantial scientific evidence to change behavior....... This is of course not true as new modes of treatment are rapidly implemented when their effect has been documented. The health care sector therefore presents a paradox: Why can changes in treatment be implemented without problems, when lean and thereby changes in work processes are so difficult? This paper will try...

METHODS FOR ORGANIZATION OF WORKING PROCESS FOR GAS-DIESEL ENGINE

Directory of Open Access Journals (Sweden)

G. A. Vershina

2017-01-01

Full Text Available Over the past few decades reduction in pollutant emissions has become one of the main directions for further deve- lopment of engine technology. Solution of such problems has led to implementation of catalytic post-treatment systems, new technologies of fuel injection, technology for regulated phases of gas distribution, regulated turbocharger system and, lately, even system for variable compression ratio of engine. Usage of gaseous fuel, in particular gas-diesel process, may be one of the means to reduce air pollution caused by toxic substances and meet growing environmental standards and regulations. In this regard, an analysis of methods for organization of working process for a gas-diesel engine has been conducted in the paper. The paper describes parameters that influence on the nature of gas diesel process, it contains graphics of specific total heat consumption according to ignition portion of diesel fuel and dependence of gas-diesel indices on advance angle for igni-tion portion injection of the diesel fuel. A modern fuel system of gas-diesel engine ГД-243 has been demonstrated in the pa- per. The gas-diesel engine has better environmental characteristics than engines running on diesel fuel or gasoline. According to the European Natural & bio Gas Vehicle Association a significant reduction in emissions is reached at a 50%-substitution level of diesel fuel by gas fuel (methane and in such a case there is a tendency towards even significant emission decrease. In order to ensure widespread application of gaseous fuel as fuel for gas-diesel process it is necessary to develop a new wor- king process, to improve fuel equipment, to enhance injection strategy and fuel supply control. A method for organization of working process for multi-fuel engine has been proposed on the basis of the performed analysis. An application has been submitted for a patent.

Creation of technological bases of struggle with generation of natural gas hydrates

International Nuclear Information System (INIS)

Asadov, M.M.; Alieva, S.A.

2005-01-01

Chemical technological access, permitting directed of intensify processes prevention of gas hydrates during motion of the gas-liquid current of natural gas in the borehole cavity of natural gas-borehole cavity have been engineered. Determined technological regimes of gas current conditioning, permitting create nonequilibrium state providing condition for reversible process

The lean-combustion gasoline engine. A concept with global application; Der magerbetriebene Ottomotor. Ein Konzept fuer den weltweiten Einsatz

Energy Technology Data Exchange (ETDEWEB)

Kemmler, Roland; Enderle, Christian; Waltner, Anton; Vent, Guido [Daimler AG, Stuttgart (Germany)

2013-08-01

After Mercedes-Benz launched the first lean-combustion gasoline engines with spray-guided combustion in 2006, it rolled out this technology on a broad level based on the engine model series featuring the BlueDIRECT combustion system. Although these engines raise the bar among competitors in terms of fuel consumption, they are currently available only in countries that offer sulfur-free fuel. This leads to the question of what technical measures or altered constraints would be necessary to allow this environmentally-friendly technology to enjoy more widespread use. The following paper discusses how the accessibility of the lean-combustion technology can be improved by focusing primarily on the USA and China as potential markets. Challenges are involved, of course, in particular with respect to fuel quality and emissions as well as the market-specific implications for on-board diagnostics. By working to further reduce fuel sulfur content, however, lean-combustion gasoline engines could also be offered in the aforementioned regions in the mid-term. (orig.)

Natural gas product and strategic analysis

Energy Technology Data Exchange (ETDEWEB)

Layne, A.W.; Duda, J.R.; Zammerilli, A.M.

1993-12-31

Product and strategic analysis at the Department of Energy (DOE)/Morgantown Energy Technology Center (METC) crosscuts all sectors of the natural gas industry. This includes the supply, transportation, and end-use sectors of the natural-gas market. Projects in the Natural Gas Resource and Extraction supply program have been integrated into a new product focus. Product development facilitates commercialization and technology transfer through DOE/industry cost-shared research, development, and demonstration (RD&D). Four products under the Resource and Extraction program include Resource and Reserves; Low Permeability Formations; Drilling, Completion, and Stimulation: and Natural Gas Upgrading. Engineering process analyses have been performed for the Slant Hole Completion Test project. These analyses focused on evaluation of horizontal-well recovery potential and applications of slant-hole technology. Figures 2 and 3 depict slant-well in situ stress conditions and hydraulic fracture configurations. Figure 4 presents Paludal Formation coal-gas production curves used to optimize the hydraulic fracture design for the slant well. Economic analyses have utilized data generated from vertical test wells to evaluate the profitability of horizontal technology for low-permeability formations in Yuma County, Colorado, and Maverick County, Texas.

45th IGE (Institute of Gas Engineers) Autumn Meeting

Energy Technology Data Exchange (ETDEWEB)

Riley, T; De Winton, C

1980-01-01

Topics discussed at the 45th Institute of Gas Engineers Autumn Meeting (London, 1979) are outlined, including safety standards and recommendations for gas transmission and distribution systems, gas characteristics and utilization, heat transfer research, gas receiver stresses, the potential of hydrogen as an energy fuel, gas appliances and controls, pipe failure, refactories in gasifiers, synthetic natural gas, coal conversion techniques, and technological innovations.

Natural Gas

OpenAIRE

Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

2010-01-01

Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

Engineering Probiotics that Improve Warfighter Performance by Maintaining Lean Body Mass and Inhibiting Anxiety

Science.gov (United States)

2017-10-03

From - To) 03/10/2017 Final Technical Report 15-05-14 to 14-05-17 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Engineering probiotics that improve...ABSTRACT The overall goal of this work is to engineer "synthetic probiotics": orally-administered gut bacteria that sense and compute the metabolic...Final Technical Report Grant number: ONR N00014-14-1-0487 Title: Engineering probiotics that improve warfighter performance by maintaining lean body

Natural gas passenger vehicles: challenges and way forward

International Nuclear Information System (INIS)

Sahari, B. B.; Hamouda, A. M. S.

2006-01-01

Natural gas vehicles have been used in the world for many years: at present, there are about 3 million vehicles running on natural gas and many governments and vehicle manufactures are involved in programs for further developing the market for natural gas vehicles. In comparison to other forms of energy for vehicles, natural gas (NG) engenders low pressures on the environment. At the same time, because of its technical characteristics, NG is very suitable for motor use. The economic advantage of converting a vehicles (NGVs) would be expected to attract the interest of a great number of people, and achieve rapid and widespread diffusion. On the contrary, traditional fuels still dominate the scene, and show no sign of going out of fashion. The use of natural gas as automotive fuel has become of national and worldwide interests particularly so with the recent increase in petrol price, depleting petrol reserves and stringent control of exhaust emission levels. For automotive applications, shifting from petrol to gas needs technological research and development. Within the framework of the reciprocating piston based engine this development is very challenging with technological issues of low range, refueling infrastructure, heavy fuel storage, safety, emissions control and gas operating pressures. Other issues include available expertise and experience in research management. This paper describes the advances being made with passenger vehicles natural gas engines worldwide and in Malaysia more specific. The significant milestones in the development of NGV in Malaysia and the rationale behind the choice of NGV industry including the NGV vehicle population growth, the development of service station as well as the expansion of the sales volume will be illustrated. The presentation presents also development stages and advances in development, fabrication and testing a Compressed Natural Gas Direct Injection vehicle and NGV refueling station. This presentation discuses the

Natural gas trends

International Nuclear Information System (INIS)

Anderson, A.

1991-01-01

This book provides data on many facets of the natural gas industry. Topics include: Canadian, Mexican; US natural gas reserves and production; Mexican and US natural gas consumption; market conditions for natural gas in the US; and Canadian natural gas exports

Effect of Hydrogen and Hydrogen Enriched Compressed Natural Gas Induction on the Performance of Rubber Seed Oil Methy Ester Fuelled Common Rail Direct Injection (CRDi Dual Fuel Engines

Directory of Open Access Journals (Sweden)

Mallikarjun Bhovi

2017-06-01

Full Text Available Renewable fuels are in biodegradable nature and they tender good energy security and foreign exchange savings. In addition they address environmental concerns and socio-economic issues. The present work presents the experimental investigations carried out on the utilization of such renewable fuel combinations for diesel engine applications. For this a single-cylinder four-stroke water cooled direct injection (DI compression ignition (CI engine provided with CMFIS (Conventional Mechanical Fuel Injection System was rightfully converted to operate with CRDi injection systems enabling high pressure injection of Rubber seed oil methyl ester (RuOME in the dual fuel mode with induction of varied gas flow rates of hydrogen and hydrogen enriched CNG (HCNG gas combinations. Experimental investigations showed a considerable improvement in dual fuel engine performance with acceptable brake thermal efficiency and reduced emissions of smoke, hydrocarbon (HC, carbon monoxide (CO and slightly increased nitric oxide (NOx emission levels for increased hydrogen and HCNG flow rates. Further CRDi facilitated dual fuel engine showed improved engine performance compared to CMFIS as the former enabled high pressure (900 bar injection of the RuOME and closer to TDC (Top Dead Centre as well. Combustion parameters such as ignition delay, combustion duration, pressure-crank angle and heat release rates were analyzed and compared with baseline data generated. Combustion analysis showed that the rapid rate of burning of hydrogen and HCNG along with air mixtures increased due to presence of hydrogen in total and in partial combination with CNG which further resulted into higher cylinder pressures and energy release rates. However, sustained research that can provide feasible engine technology operating on such fuels in dual fuel operation can pave the way for continued fossil fuel usage.

Natural gas : nirvana

International Nuclear Information System (INIS)

Stonehouse, D.

2001-01-01

Despite completing 8,900 gas wells in year 2000, the deliverability of natural gas out of the Western Canadian Sedimentary Basin (WCSB) was stagnant which has left many analysts wondering whether the basin has reached its limit. It also leaves many wondering if gas producers will be able to meet the strong demand for natural gas in the future. Nearly all new electrical generation being built in the U.S. is gas-based due to strict new environmental standards limiting the growth in hydro and coal-powered generation. Any future coal plants will use gasification technology and combined cycle turbines. Combined cycle turbines developed by Boeing and Lockheed are more efficient than combustion turbines, making gas more competitive with fuel alternatives. The lack of growth in natural gas supply has left storage levels near record lows. Demand is expected to increase in 2001 by 3.2 per cent to 23 trillion cubic feet in the U.S. Longer term, major new reserves must be brought on stream to meet this demand. It was noted that the easy discoveries within the WCSB have been made. The new plays are smaller, more technically complex and expensive which suggests that more investment is needed in training geologists, geophysicists and petroleum engineers to find new reserves. The Canadian Energy Research Institute agrees that there is enough gas in Alberta and British Columbia to meet current demands but efforts must shift towards drilling in the foothills front and northwest regions of Alberta to increase deliverability. Brief notes on several gas finds by various oil and gas companies in the area were presented. The article also discussed the huge untapped potential of northern reserves. Analysts have noted 44 Tcf of proven reserve, with a potential of 165 Tcf. In addition, new pipelines from the Alaskan North Slope and the Mackenzie Delta could transport nearly 2 Tcf annually to market. Wells drilled by Chevron and Paramount at Fort Liard in 1999 initially flowed at rates up to

Governmental support for driving on natural gas. An outline of political factors

International Nuclear Information System (INIS)

Van der Knoop, J.; Overmars, P.

2005-09-01

Government support is crucial for the viability of the market for natural gas as engine fuel. This outlook focuses on the viewpoint of the government and the large political parties in this respect. At first this study was meant to be a brief outlook, but the study expanded in two directions. First of all, more attention was paid to the discussion on the use of natural gas as engine fuel and in line with the various incentivisation regulations in the context of more general greening taxes. The stimulation of driving on natural gas cannot be separated from similar measures for other (clean(er)) fuels. Secondly, based on the obtained insights, conclusions were drawn on the chances for government subsidy for driving on natural gas. Finally, attention has also been paid to the question if politicians recognise and acknowledge the intermediary role of natural gas in the transition towards sustainable fuels. If this is the case, the parliament will probably put more pressure on the government to stimulate driving on natural gas in view of the additional value of investments in the natural gas fuel infrastructure.[mk] [nl

GAS TURBINE ENGINES CONSUMING BIOGAS

Directory of Open Access Journals (Sweden)

Е. Ясиніцький

2011-04-01

Full Text Available A problem of implementation of biofuel for power plants of big capacity was considered in thisarticle. Up to date in the world practice a wide implementation of biogas plants of low and medialcapacity are integrated. It is explained by the big amount of enterprises in which relatively smallvolumes of organic sediment excrete in the process of its activity. An emphasis of article is on thatenterprises, which have big volumes of sediments for utilizing of which module system of medialcapacity biogas plants are non-effective. The possibility of using biogas and biomethane as a fuelfor gas turbine engine is described. The basic problems of this technology and ways of its solutionsare indicated. Approximate profitability of biogas due to example of compressor station locatednearby poultry factory was determined also. Such factors as process characteristics of engine withcapacity of 5 MW, approximate commercial price for natural gas and equipment costs due toofficial sources of “Zorg Ukraine” company was taken into consideration. The necessity forproviding researches on influence of biogas on the process characteristics of gas turbine engine andits reliability, constructing modern domestic purification system for biogas was shown.

Concept for a LNG Gas Handling System for a Dual Fuel Engine

Directory of Open Access Journals (Sweden)

Michael Rachow

2017-09-01

Full Text Available Nowadays, ships are using LNG as main engine fuel because based on the facts that LNG has no sulphur content, and its combustion process, LNG produces low NOx content compared to heavy fuel oil and marine diesel oil. LNG is not only produces low gas emission, but may have economic advantages. In the engine laboratory of maritime studies department in Warnemunde, Germany, there is a diesel engine type MAN 6L23/30 A, where the mode operation of these engine would be changed to dual fuel engine mode operation. Therefore, in this thesis, the use dual fuel engine will be compared where it will utilize natural gas and marine diesel oil and select the required components for fuel gas supply system. By conducting the process calculation, engine MAN 6L23/30 A requires the capacity natural gas of 12.908  for 5 days at full load. A concept for LNG supply system would be arranged from storage tank until engine manifold. Germanischer Lloyd and Project Guide of dual fuel engine will be used as a guidelines to develop an optimal design and arrangement which comply with the regulation.

Natural gas and Brazilian energetic matrix; Gas natural no Brasil

Energy Technology Data Exchange (ETDEWEB)

Moraes, Ricardo Luchese de [White Martins S.A., Rio de Janeiro, RJ (Brazil)

1997-07-01

Recent projection of the market in global scale shows a tendency in natural gas using replacing mostly the fuel oil. Its market share well increase from 21.1% in 1994 to 24.0% in 2010. The annual energetic use will reach 29.23 x 10{sup 9} Gcal in 2010 (8990 million Nm{sup 3} natural gas/day) versus 18.90 x 10{sup 9} Gcal in 1994 (5810 million Nm{sup 3} natural gas/day). For Brazil, its consumption will increase from 8.7 million Nm{sup 3} natural gas/day in 1994 to 35.9 million Nm{sup 3} natural gas/day in 2010. Projects like Brazil-Bolivia natural gas pipeline, will supply 18 million Nm{sup 3} natural gas/day, which expected to start-up before the year 2000. This projects will supply the Brazilian southern regions, that do not consume natural gas at the current moment. Although there are many different kind of natural gas consumption in the industry this paper presents the technical and economical estimate of the injection in the blast furnace operating with coke or charcoal. The process simulation is done assisted by math modeling developed by White Martins/Praxair Inc. (author)

O conceito de Lean Office aplicado a um ambiente industrial com produção ETO – Engineer-to-Order

Directory of Open Access Journals (Sweden)

Filipe Marafon de Paoli

2014-01-01

Full Text Available The concepts and practices of lean manufacturing have been used by companies to obtain improvements in the efficiency levels of their manufacturing facilities. However, waste in manufacturing firms is not limited to the production floor; it is also present in administrative areas. Hence, the objective of this paper was to verify if Lean Office concepts can be applied in engineering and in the development of projects of companies with Engineer-to-Order (ETO production systems. To achieve this, an action research inquiry was carried out in a heavy equipment manufacturing firm that follows ETO principles. The selected non-manufacturing area was the Hydraulic Systems Engineering Department. As a result of this research, it was possible to verify that the principles of the Lean Office applied to the engineering and development of products in the company operating in an ETO environment can be effectively used, eliminating several types of waste existing in that area.

Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

KAUST Repository

Zhou, Zhen; Hernandez Perez, Francisco; Shoshin, Yuriy; van Oijen, Jeroen A.; de Goey, Laurentius P.H.

2017-01-01

The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

KAUST Repository

Zhou, Zhen

2017-04-12

The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

Trace gas emissions from burning Florida wetlands

Science.gov (United States)

Cofer, Wesley R.; Levine, Joel S.; Winstead, Edward L.; Lebel, Peter J.; Koller, Albert M.; Hinkle, C. Ross

1990-02-01

Measurements of biomass burn-produced trace gases are presented that were obtained using a helicopter at low altitudes above burning Florida wetlands on November 9, 1987, and from both helicopter and light-aircraft samplings on November 7, 1988. Carbon dioxide (CO2) normalized emission ratios (ΔX/ΔCO2; V/V; where X is trace gas) for carbon monoxide (CO), hydrogen (H2), methane (CH4), total nonmethane hydrocarbons (TNMHC), and nitrous oxide (N2O) were obtained over burning graminoid wetlands consisting primarily of Spartina bakeri and Juncus roemerianus. Some interspersed scrub oak (Quercus spp) and saw palmetto (Screnoa repens) were also burned. No significant differences were observed in the emission ratios determined for these gases from samples collected over flaming, mixed, and smoldering phases of combustion during the 1987 fire. Combustion-categorized differences in emission ratios were small for the 1988 fire. Combustion efficiency was relatively good (low emission ratios for reduced gases) for both fires. We believe that the consistently low emission ratios were a unique result of graminoid wetlands fires, in which the grasses and rushes (both small-size fuels) burned rapidly down to standing water and were quickly extinguished. Consequently, the efficiency of the combustion was good and the amount and duration of smoldering combustion was greatly diminished.

CFD analysis of combustion of natural gas and syngas from biomass pyrolysis in the combustion chamber of a micro gas turbine

Energy Technology Data Exchange (ETDEWEB)

Fantozzi, Francesco; Laranci, Paolo; D' Alessandro, Bruno [University of Perugia (DII/UNIPG) (Italy). Dept. of Industrial Engineering], Emails: fanto@unipg.it, paolo.laranci@unipg.it, dalessandro@bio-net.it

2009-07-01

Micro gas turbines (MGT) can be profitably used for the production of distributed energy (DE), with the possibility to use gaseous fuels with low BTU derived from biomass or waste through the pyrolysis or gasification processes. These synthesis gases (SG) show significant differences with respect to natural gas (NG), in terms of composition, calorific value, content of hydrogen, tar and particulate matter content; such differences can be turn into problems of ignition, instability burning, difficulties in controlling the emissions and fouling. CFD analysis of the combustion process is an essential tool for identifying the main critical arising in using these gases, in order to modify existing geometries and to develop new generation of combustor for use with low BTU gases. This paper describes the activities of experimental and numerical analysis carried out to study the combustion process occurring inside an existing annular Rich-Quench-Lean (RQL) Combustion Chamber (CC) of a 80 kW MGT. In the paper some results of a CFD study of the combustion process performed with an original developed chemical models are reported in terms of temperature and velocity distributions inside the CC and in terms of compositions of turbine inlet gas and of its thermodynamic parameters (mass flow, temperature, pressure). An evaluation of pollutant emissions of CO, CO{sub 2} and NOx and a comparison with the available experimental data relating to the case of combustion of NG is also provided in the paper. Moreover, the carried out investigation concerns the case of operation with a SG fuel derived from biomass in an Integrated Pyrolysis Regenerated Plant (IPRP). (author)

Alternative-fueled truck demonstration natural gas program: Caterpillar G3406LE development and demonstration

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

In 1990, the California Energy Commission, the South Coast Air Quality Management District, and the Southern California Gas Company joined together to sponsor the development and demonstration of compressed natural gas engines for Class 8 heavy-duty line-haul trucking applications. This program became part of an overall Alternative-Fueled Truck Demonstration Program, with the goal of advancing the technological development of alternative-fueled engines. The demonstration showed natural gas to be a technically viable fuel for Class 8 truck engines.

[Fuel substitution of vehicles by natural gas: Summaries of four final technical reports

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-05-01

This report contains summary information on three meetings and highlights of a fourth meeting held by the Society of Automotive Engineers on natural gas fueled vehicles. The meetings covered the following: Natural gas engine and vehicle technology; Safety aspects of alternately fueled vehicles; Catalysts and emission control--Meeting the legislative standards; and LNG--Strengthening the links.

Optimalisation Of Oxide Burn-Up Enhanced For RSG-Gas Core

International Nuclear Information System (INIS)

Tukiran; Sembiring, Tagor Malem

2000-01-01

Strategy of fuel management of the RSG-Gas core has been changed from 6/1 to 5/1 pattern so the evaluation of fuel management is necessary to be done. The aim of evaluation is to look for the optimal fuel management so that the fuel can be stayed longer in the core and finally can save cost of operation. Using Batan-EQUIL-2D code did the evaluation of fuel management with 5/1 pattern. The result of evaluation is used to choose which one is more advantage without break the safety margin which is available in the Safety Analysis Report (SAR) firstly, the fuel management was calculated with core excess reactivity of 9,2% criteria. Secondly, fuel burn-up maximum of 56% criteria and the last, fuel burn-up maximum of 64% criteria. From the result of fuel management calculation of the RSG-Gas equilibrium core can be concluded that the optimal RSG-Gas equilibrium core with 5/1 pattern is if the fuel burn-up maximum 64% and the energy in a cycle of operation is 715 MWD. The fuel can be added one more step in the core without break any safety margin. It means that the RSG-Gas equilibrium core can save fuel and cost reduction